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Repaired morphology of CO_(2)laser rapid ablation mitigation of fused silica and its influence on downstream light modulation

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Science China(Technological Sciences) 2022年第5期65卷 1116-1126页

作者： TAN Chao ZHAO LinJie CHEN MingJun CHENG Jian ZHANG Yu ZHANG Jiong YANG Hao YIN ZhaoYang State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin150001China Department of Mechanical Engineering National University of SingaporeSingapore117575Singapore

The threat of cascading damage to downstream components caused by the light modulation intensification of laser repaired morphology on the surface of fused silica optics cannot be ignored in high-power laser *** paper uses the angular spectrum diffraction theory based on the analysis of repaired surface morphology of CO_(2)laser rapid ablation mitigation to study the influence of different repaired morphologies on the downstream 355 nm laser *** show that the arc-shaped laser processing lines on the repaired surface are formed by the residual height superposition of the material after laser scanning of two adjacent layers,and the short-pulse laser can substantially suppress the heat-affected zone of the repaired *** offaxis ring caustic and on-axis hotspot are sequentially generated in the downstream modulated light fields of the conical repaired sites with different diameters.A secondary peak with modulation larger than 3 emerges downstream of the modulation ***,the maximum modulation and the secondary peak increase with the diameter and cone angle of the repaired site,and the position of the secondary peak appears farther away from the rear *** modulations of three repaired sites with cone angles of 15°,20°,and 25°can finally be stabilized below ***,the downstream optics should be installed far away from the positions where the maximum modulation and the secondary peak ***,the maximum value and the secondary peak of the downstream light modulation of double repaired sites are larger than that of the single repaired site,and both rise as the repaired sizes ***,large-scale and large-size repairing of multiple surface damages in the same area should be avoided in the laser repairing of fused silica.

关键词： fused silica laser repairing morphology light modulation secondary peak double repaired sites

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Fractal and multifractal analysis of network teletraffic 12

Fractal and multifractal analysis of network teletraffic

引用

13th International Conference on Computer systems and Technologies, CompSysTech 2012

作者： Gospodinova, Evgeniya Gospodinov, Mitko Institute of System Engineering and Robotics Bulgarian Academy of Sciences Bulgaria

ISBN: (纸本)9781450311939

In the paper is investigated fractal and multifractal properties of the real network traffic, such as Ethernet, TCP, UDP and the simulated fractal (self-similarity) traffic based on the fractional Gaussian noise (FGN) process. The obtained results show that the modern network traffic may be better characterized by multifractal analysis, since this approach describes both local and global features of the process. The broad multifractal Legendre spectrum of TCP, UDP and Ethernet traffic indicates multifractal behavior, whereas the narrow Legendre spectrum of FGN process indicates loss of multifractality. Copyright ©2012 ACM.

关键词： Fractals

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Three-layer intelligence of planetary exploration wheeled mobile robots:Robint,virtint,and humint

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Science China(Technological Sciences) 2015年第8期58卷 1299-1317页

作者： DING Liang GAO HaiBo DENG ZongQuan LI YuanKai LIU GuangJun YANG HuaiGuang YU HaiTao State Key Laboratory of Robotics and System Harbin Institute of Technology School of Aeronautics and Astronautics University of Electronic Science and Technology of China Department of Aerospace Engineering Ryerson University

The great success of the Sojourner rover in the Mars Pathfinder mission set off a global upsurge of planetary exploration with autonomous wheeled mobile robots(WMRs),or *** WMRs are among the most intelligent space systems that combine robotic intelligence(robint),virtual intelligence(virtint),and human intelligence(humint) *** article extends the architecture of the three-layer intelligence stemming from successful Mars rovers and related technologies in order to support the R&D of future tele-operated robotic ***-layer human-machine interfaces are suggested to support the integration of humint from scientists and engineers through supervisory(Mars rovers) or three-dimensional(3D) predictive direct tele-operation(lunar rovers).The concept of multilevel autonomy to realize robint,in particular,the Coupled-Layer Architecture for Robotic Autonomy developed for Mars rovers,is *** challenging issues of intelligent perception(proprioception and exteroception),navigation,and motion control of rovers are discussed,where the terrains' mechanical properties and wheel-terrain interaction mechanics are considered to be ***-level virtual simulation architecture to realize virtint is *** technologies of virtint are summarized:virtual planetary terrain modeling,virtual intelligent rover,and wheel-terrain interaction *** generalized three-layer intelligence framework is also applicable to other systems that require human intervention,such as space robotic arms,robonauts,unmanned deep-sea vehicles,and rescue robots,particularly when there is considerable time delay.

关键词： planetary exploration rovers robot intelligence virtual intelligence three-layer architecture

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Temperature field characteristics of CF/PEEK thermoplastic composites formed by automated fiber placement using hot gas torch with slit structure nozzle

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Chinese Journal of Aeronautics 2024年第6期37卷 392-409页

作者： Ziang JIN Shouzheng SUN Sunil Chandrakant JOSHI Zhenyu HAN Hongya FU State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China School of Mechanical and Aerospace Engineering Nanyang Technological UniversitySingapore 639798Singapore

In-situ consolidation forming of high-performance thermoplastic composites by Automated Fiber Placement(AFP)is of significant interest in *** the laying process,the heating temperature has a great influence on the quality of the formed components.A threedimensional heat transfer finite element model of Carbon Fiber(CF)/Polyether Ether Ketone(PEEK)heated by Slit Structure Nozzle Hot Gas Torch(SSNHGT)assisted AFP is *** influence of gas flow rate,heat transfer distance,and laying speed on heating temperature is *** results show that the overall temperature increases and then decreases as the gas flow rate *** the increase in heat transfer distance and laying speed,the overall temperature ***,the gas flow rate has the greatest influence on the temperature of CF/PEEK being heated,followed by the laying speed and finally the heat transfer ***,the model can also be extended to other fiber-reinforced polymer composites formed by hot gas torch assisted AFP,which can guide the optimization of process parameters for subsequent heating temperature control.

关键词： Fiber reinforced plastics Thermoplastics Heating temperature Automated fiber placement CF/PEEK

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A review of structures,verification,and calibration technologies of space robotic systems for on-orbit servicing

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Science China(Technological Sciences) 2021年第3期64卷 462-480页

作者： DING XiLun WANG YeCong WANG YaoBing XU Kun Robotics Institute Beihang UniversityBeijing 100191China Beijing Institute of Spacecraft System Engineering Beijing Key Laboratory of Intelligent Space Robotic Systems Technology and ApplicationsBeijing 100094China

Recently,with the rapid development of aerospace technology,an increasing number of spacecraft is being launched into ***,the demands for on-orbit servicing(OOS)missions are rapidly *** robotics is one of the most promising approaches for various OOS missions;thus,research on space robotics technologies for OOS has attracted increased attention from space agencies and universities *** this paper,we review the structures,ground verification,and onorbit kinematics calibration technologies of space robotic systems for ***,we systematically summarize the development of space robotic systems and OOS programs based on space ***,according to the structures and applications,these systems are divided into three categories:large space manipulators,humanoid space robots,and small space *** to the capture mechanisms adopted,the end-effectors are systematically ***,the ground verification facilities used to simulate a microgravity environment are summarized and ***,the on-orbit kinematics calibration technologies are discussed and analyzed compared with the kinematics calibration technologies of industrial manipulators with regard to four ***,the development trends of the structures,verification,and calibration technologies are discussed to extend this review work.

关键词： space robotic system on-orbit servicing large space manipulator humanoid space robot verification kinematics calibration

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Numerical and experimental studies of hydrodynamics of flapping foils

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Journal of Hydrodynamics 2018年第2期30卷 258-266页

作者： Kai Zhou Jun-kao Liu Wei-shan Chen College of Mechanical and Electronic Engineering Shandong Agricultural University Taian 271018 China State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin 150001 China

The flapping foil based on bionics is a sort of simplified models which imitate the motion of wings or fins of fish or birds. In this paper, a universal kinematic model with three degrees of freedom is adopted and the motion parallel to the flow direction is considered. The force coefficients, the torque coefficient, and the flow field characteristics are extracted and analyzed. Then the propulsive efficiency is calculated. The influence of the motion parameters on the hydrodynamic performance of the bionic foil is studied. The results show that the motion parameters play important roles in the hydrodynamic performance of the flapping foil. To validate the reliability of the numerical method used in this paper, an experiment platform is designed and verification experiments are carried out. Through the comparison, it is found that the numerical results compare well with the experimental results, to show that the adopted numerical method is reliable. The results of this paper provide a theoretical reference for the design of underwater vehicles based on the flapping propulsion.

关键词： Biological fluid dynamics flapping foil hydrodynamic performance numerical simulation

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Adaptive RISE Control for Dual-Arm Unmanned Aerial Manipulator systems with Deep Neural Networks

arXiv

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arXiv 2025年

作者： Wang, Yang Yu, Hai Wu, Shizhen Yang, Zhichao Han, Jianda Fang, Yongchun Liang, Xiao Institute of Robotics and Automatic Information System College of Artificial Intelligence Tianjin Key Laboratory of Intelligent Robotics Nankai University Tianjin300350 China Engineering Research Center of Trusted Behavior Intelligence Ministry of Education Nankai University Tianjin300350 China

The unmanned aerial manipulator system, consisting of a multirotor UAV (unmanned aerial vehicle) and a manipulator, has attracted considerable interest from researchers. Nevertheless, the operation of a dual-arm manipulator poses a dynamic challenge, as the CoM (center of mass) of the system changes with manipulator movement, potentially impacting the multirotor UAV. Additionally, unmodeled effects, parameter uncertainties, and external disturbances can significantly degrade control performance, leading to unforeseen dangers. To tackle these issues, this paper proposes a nonlinear adaptive RISE (robust integral of the sign of the error) controller based on DNN (deep neural network). The first step involves establishing the kinematic and dynamic model of the dual-arm aerial manipulator. Subsequently, the adaptive RISE controller is proposed with a DNN feedforward term to effectively address both internal and external challenges. By employing Lyapunov techniques, the asymptotic convergence of the tracking error signals are guaranteed rigorously. Notably, this paper marks a pioneering effort by presenting the first DNN-based adaptive RISE controller design accompanied by a comprehensive stability analysis. To validate the practicality and robustness of the proposed control approach, several groups of actual hardware experiments are conducted. The results confirm the efficacy of the developed methodology in handling real-world scenarios, thereby offering valuable insights into the performance of the dual-arm aerial manipulator system. Copyright © 2025, The Authors. All rights reserved.

关键词： Lyapunov functions

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Factors governing heat affected zone during wire bonding

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Transactions of Nonferrous Metals Society of China 2009年第S02期19卷 490-494页

作者： SUN Li-ning LIU Yue-tao LIU Yan-jie State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150080China School of Mechanical Engineering Shandong University of TechnologyZibo 255049China

In the wire bonding process of microelectronic packaging,heat affect zone(HAZ)is an important factor governing the loop profile of *** height of loop is affected by the length of the *** governing the HAZ were *** investigate this relationship,experiments were done for various sizes of wire and free air ball(FAB).Electric flame-off(EFO)current, EFO time,EFO gap and recrystallization were also *** results show that as the size of FAB becomes larger,the length of HAZ *** the increase of EFO current and time,the length of HAZ becomes *** FAB forms at the same parameter the length of HAZ becomes shorter with the high temperature of recrystallization.

关键词： heat affected zone wire bonding electric flame off free air ball

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Adaptive Backstepping Tracking Control of a 6-DOF Unmanned Helicopter

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IEEE/CAA Journal of Automatica Sinica 2015年第1期2卷 19-24页

作者： Bin Xian Jianchuan Guo Yao Zhang the Institute of Robotics and Autonomous System Tianjin Key Laboratory of Process Measurement and Control School of Electrical Engineering and AutomationTianjin University

This paper presents an adaptive backstepping control design for a class of unmanned helicopters with parametric uncertainties. The control objective is to let the helicopter track some pre-defined position and yaw trajectories. In order to facilitate the control design, we divide the helicopter's dynamic model into three subsystems. The proposed controller combines the backstepping method with online parameter update laws to achieve the control objective. The global asymptotical stability (GAS) of the closed-loop system is proved by a Lyapunov based stability analysis. Numerical simulations demonstrate that the controller can achieve good tracking performance in the presence of parametric uncertainties. © 2014 Chinese Association of Automation.

关键词： Backstepping Closed loop control systems Closed loop systems Controllers Flight dynamics Helicopters

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Ground plane detection using visual and inertial data fusion 5

Ground plane detection using visual and inertial data fusion

引用

5th IEEE International Conference on Electronics, Circuits and systems, ICECS 1998

作者： Lobo, Jorge Dias, Jorge Institute of System and Robotics Electrical Engineering Department University of Coimbra Portugal

ISBN: (纸本)0780350081

In mobile systems the position and attitude of the active vision system's cameras can be hard to determine. Inertial sensors coupled to the active vision system can provide valuable information, as happens with the vestibular system in human and other animals. In this article, we present our integrated inertial and vision systems. The active vision system has a set of stereo cameras capable of vergence, with a common baseline, pan and tilt, and an implemented process of visual fixation. An inertial system prototype, based on low-cost sensors, was built. The inertial sensor data is used to segment the ground plane in the images. For on-the-fly visualisation of the segmented images and the detected ground points a VRML viewer is used. © 1998 IEEE.

关键词： Data fusion

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