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Understanding the Machining Process of Hierarchical Micro/Nanograting Structures Used for Optical Variable Device

Chinese Journal of mechanical engineering 2025年第1期38卷 161-185页

作者： Yanquan Geng Wenhan Zhu Xiaosong Zhang Aoxiang Zhang Yongda Yan Hailong Cui Bo Xue Jiqiang Wang TState Key Laboratory of Robotics and Systems Robotics InstituteHarbin Institute of TechnologyHarbin 150080China Sichuan Precision and Ultra-Precision Machining Engineering Technology Center Chengdu 610200China College of Mechanical and Electrical Engineering Northeast Forestry UniversityHarbin 150040China

Hierarchical micro/nanograting structures have attracted increasing attention owing to their significant applications in the fields of structural coloring,anti-counterfeiting,and ***,the fabrication of hierarchical micro/nanograting structures is important for these *** this study,a strategy for machining hierarchical micro/nanograting structures is developed by controlling the tool movement trajectory.A coupling Euler-Lagrange finite element model is established to simulate the machining *** effect of the machining methods on the nanograting formation is demonstrated,and a suitable machining method for reducing the cutting force is *** height of the nanograting decreases with an increase in the tool edge ***,optical variable devices(OVDs)are machined using an array overlap machining *** schemes for the parallel column unit crossover and column unit in the groove crossover are designed to achieve high-quality machining of *** coloring of the logo of the Harbin institute of Technology and the logo of the centennial anniversary of the Harbin institute of Technology on the surface of metal samples,such as aluminum alloys,is *** findings of this study provide a method for the fabrication of hierarchical micro/nanograting structures that can be used to prepare OVDs.

关键词： Hierarchical micro/nanograting structures Optical variable devices Finite element simulation Tool trajectory controlling

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JADFER: Exploring Spatial-Contextual Interaction With Joint Attention Dropping for Facial Expression Recognition

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IEEE Transactions on Affective Computing 2025年第2期16卷 655-668页

作者： Gao, Yu Ren, Weihong Jiang, Weibo Dong, Qian Nie, Wei Wu, Wenhao Liu, Honghai Harbin Institute of Technology State Key Lab of Robotics and Systems School of Mechanical Engineering and Automation Shenzhen518055 China

Facial Expression Recognition (FER) aims to cate-gorize emotional expressions depicted on a human face, and isa challenging task under unconstrained conditions, such as faceocclusions and pose variations. Recent methods usually adopt selfattention or cross attention to explore global or local relationshipsamong different level features. However, these methods are inclinedto focus on the redundant facial regions, causing model *** address this problem, we propose a new FER model namedJADFER, which drops the joint attention in the weight matrix toadaptively enhance facial expression representations. Specifically,our JADFER model consists of three components: Spatial Branch(SB), Contextual Branch (CB), and Spatial-Contextual Interaction(SCI). First, SB runs N paths in parallel, where a Variety loss is de-signed to guide the paths of SB to focus on different discriminativeregions. Meanwhile, CB abstracts the contextual facial represen-tations using self attention with Joint Attention Dropping (JAD).Then, the SCI adopts the spatial features from SB to query thecontextual representations from CB through cross attention withJAD, which regulates the attention weights by dropping the similaractivations to further enhance the facial embeddings. Experimen-tal results demonstrate that the proposed model outperforms thestate-of-the-art methods on several FER benchmarks. © 2010-2012 IEEE.

关键词： Face recognition

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Strong Current-State Opacity Verification of Discrete-Event systems Modeled With Time Labeled Petri Nets

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IEEE/CAA Journal of Automatica Sinica 2025年第1期12卷 54-68页

作者： Tao Qin Li Yin Gaiyun Liu Naiqi Wu Zhiwu Li the Institute of Systems Engineering Macau University of Science and Technology IEEE the School of Electro-Mechanical Engineering Xidian University

This paper addresses the verification of strong currentstate opacity with respect to real-time observations generated from a discrete-event system that is modeled with time labeled Petri nets. The standard current-state opacity cannot completely characterize higher-level security. To ensure the higher-level security requirements of a time-dependent system, we propose a strong version of opacity known as strong current-state opacity. For any path(state-event sequence with time information)π derived from a real-time observation that ends at a secret state, the strong current-state opacity of the real-time observation signifies that there is a non-secret path with the same real-time observation as π. We propose general and non-secret state class graphs, which characterize the general and non-secret states of time-dependent systems, respectively. To capture the observable behavior of non-secret states, a non-secret observer is ***, we develop a structure called a real-time concurrent verifier to verify the strong current-state opacity of time labeled Petri nets. This approach is efficient since the real-time concurrent verifier can be constructed by solving a certain number of linear programming problems.

关键词： Discrete-event system real-time observation strong current-state opacity time labeled Petri net

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Towards understanding the surface rippling process by periodic reciprocal nanoscratching

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Friction 2023年第10期11卷 1815-1828页

作者： Zihan LI Yongda YAN Jiqiang WANG Chen LI Yanquan GENG State Key Laboratory of Robotics and Systems Robotics InstituteHarbin Institute of TechnologyHarbin 150080China Center for Precision Engineering Harbin Institute of TechnologyHarbin 150001China

The bundle structure formed perpendicular to the scratching direction is a type of wear-induced structure for *** this study,the formation mechanism of bundle structures on polycarbonate(PC)surfaces is investigated by reciprocal scratching *** on the analysis of the morphologies,friction forces,and height signals,the formation of the bundle structure is *** influence of scratching parameters,including the feed value and scratching direction,on the formation of the bundle structure is also *** is found that the bundle structure is accumulated by the continuous stacking of the sample materials plowed by the tip in stick–slip motion,and that the stick–slip behavior is enhanced with increased scratching *** work reproduces the formation process of bundle structure in experiments for the first time and demonstrates that the stick–slip enhancement mechanism exists in the reciprocal scratching process,providing further insight into the friction behavior of polymers.

关键词： atomic force microscopy(AFM) bundle structures stick-slip friction force

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Method to improve the classification accuracy by in situ laser cleaning of painted metal scraps during laser-induced breakdown spectroscopy based sorting

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Plasma Science and Technology 2025年第3期27卷 72-86页

作者： Jaepil LEE Sungho SHIN Inseok JANG Seongguk BAE Sungho JEONG School of Mechanical and Robotics Engineering Gwangju Institute of Science and Technology123 Cheomdangwagi-roBuk-guGwangju 61005Republic of Korea

Scrap metals are typically covered with surface contaminants,such as paint,dust,and rust,which can significantly affect the emission spectrum during laser-induced breakdown spectroscopy(LIBS)based *** this study,the effects of paint layers on metal surfaces during LIBS classification were *** spectra were collected from metal surfaces painted with black and white paints by ablation with a nanosecond pulsed laser(wavelength=1064 nm,pulse width=7 ns).For the black-painted samples,the LIBS spectra showed a broad background emission,emission lines unrelated to the target metals,large shot-to-shot variation,and a relatively low signal intensity of the target metal,causing poor classification accuracy even at high shot *** the black paint layer by ablating over a wide area prior to LIBS analysis resulted in high classification accuracy with fewer shot numbers.A method to determine the number of cleaning shots necessary to obtain high classification accuracy and high throughput is proposed on the basis of the change in LIBS signal intensity during cleaning *** the white-painted samples,the paint peeled off the metal surface after the first shot,and strong LIBS signals were measured after the following shot,which were attributed to the nanoparticles generated by the ablation of the paint,allowing an accurate classification after only two *** results demonstrate that different approaches must be employed depending on the paint color to achieve high classification accuracy with fewer shot numbers.

关键词： laser induced breakdown spectroscopy(LIBS) scrap metal paint surface contaminant cleaning

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A Soft Glove with Proprioceptive Sensing and Multi-modal Haptic Feedback for VR and Telerobotic Applications

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Journal of Bionic engineering 2025年第2期22卷 684-702页

作者： Debadrata Sarkar Amit Kumar Aman Arora Human Centered Robotics and Cybernetics Group CSIR-Central Mechanical Engineering Research InstituteDurgapur713209West BengalIndia Advanced Design and Analysis Group CSIR-Central Mechanical Engineering Research InstituteDurgapur713209West BengalIndia

This research paper introduces a soft VR glove that enhances how users interact with virtual objects. It seamlessly integrates discrete modules for sensing and providing haptic feedback, encompassing tactile and kinaesthetic aspects while prioritizing wearability and natural finger movements. The glove employs custom-designed flexible bend sensors with carbon-impregnated film for in-situ joint angle tracking, simplifying the sensing system and enhancing portability. A multi-modal haptic feedback approach includes an innovative pneumatically actuated tactile feedback technique and a motor-tendon-driven kinaesthetic feedback system, providing exceptional realism in virtual object manipulation. The glove’s kinaesthetic feedback lets users perceive virtual objects’ size, shape, and stiffness characteristics. Psychophysical investigations demonstrate how readily the users acclimate to this hardware and prove each module’s effectiveness and synergistic operation. This soft VR glove represents a minimalist, lightweight, and comprehensive solution for authentic haptic interaction in virtual environments, opening new possibilities for applications in various fields.

关键词： Virtual reality and interfaces Tactile feedback Haptics and haptic interfaces Soft sensors and actuators

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Watt Linkage–Based Legged Deployable Landing Mechanism for Reusable Launch Vehicle: Principle, Prototype Design, and Experimental Validation

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engineering 2023年第1期20卷 120-133页

作者： Haitao Yu Baolin Tian Zhen Yan Haibo Gao Hongjian Zhang Huiqiang Wu Yingchao Wang Yuhong Shi Zongquan Deng State Key Laboratory of Robotics and Systems Harbin Institute of TechnologyHarbin 150080China Beijing Institute of Aerospace Systems Engineering Beijing 100076China

The reusable launch vehicle (RLV) presents a new avenue for reducing cost of space transportation. The landing mechanism, which provides landing support and impact absorption, is a vital component of the RLV at final stage of recovery. This study proposes a novel legged deployable landing mechanism (LDLM) for RLV. The Watt-II six-bar mechanism is adopted to obtain the preferred configuration via the application of the linkage variation approach. To endow the proposed LDLM with advantages of large landing support region, lightweight, and reasonable linkage internal forces, a multi-objective optimization paradigm is developed. Furthermore, the optimal scale parameters for guiding the LDLM prototype design is obtained numerically using the non-dominated sorting genetic algorithm-II (NSGA-II) evolutionary algorithm. A fully-functional scaled RLV prototype is developed by integrating the gravity-governed deploying scheme to facilitate unfolding action to avoid full-range actuation, a dual-backup locking mechanism to enhance reliability of structure stiffening as fully deployed, and a shock absorber (SA) with multistage honeycomb to offer reliable shock absorbing performance. The experimental results demonstrate that the proposed LDLM is capable of providing rapid and smooth deployment (duration less than 1.5 s) with mild posture disturbance to the cabin (yaw and pitch fluctuations less than 6°). In addition, it provides satisfactory impact attenuation (acceleration peak less than 10g (g is the gravitational acceleration)) in the 0.2 m freefall test, which makes the proposed LDLM a potential alternative for developing future RLV archetype.

关键词： Reusable launch vehicle(RLV) Deployable mechanism Optimization desi gn

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Regularizing fuel-optimal multi-impulse trajectories

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Astrodynamics 2024年第1期8卷 97-119页

作者： Kenta Oshima Department of Mechanical Systems Engineering Hiroshima Institute of TechnologyHiroshima731-5193Japan

The regularization theory has successfully enabled the removal of gravitational singularities associated with celestial *** this study,regularizing techniques are merged into a multi-impulse trajectory design framework that requires delicate computations,particularly for a fuel minimization *** variables based on the Levi–Civita or Kustaanheimo–Stiefel transformations express instantaneous velocity changes in a gradient-based direct optimization *** formulation removes the adverse singularities associated with the null thrust impulses from the derivatives of an objective function in the fuel minimization *** favorite singularity-free property enables the accurate reduction of unnecessary impulses and the generation of necessary impulses for local optimal solutions in an automatic *** of fuel-optimal multi-impulse trajectories are presented,including novel transfer solutions between a near-rectilinear halo orbit and a distant retrograde orbit.

关键词： regularization trajectory optimization fuel minimization multi-impulse trajectory

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Hybrid Robotic Arm for Autonomous Aerial Refueling

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Chinese Journal of mechanical engineering 2024年第6期37卷 429-440页

作者： Kaixuan Li Gangfeng Liu Yongsheng Gao Jie Zhao State Key Laboratory of Robotics and Systems Harbin Institute of TechnologyHarbin 150080China School of Mechatronics Engineering Harbin 150080China

Autonomous aerial refueling technology is gaining increasing attention to enhance aircraft combat *** research on autonomous refueling focuses mainly on flight control laws,with little attention to the automation of refueling *** leads to high demands on control law performance and navigation accuracy,making it difficult to ensure *** address this,we propose a robotic arm system capable of automatic docking during the flexible aerial refueling *** system uses a conical kinematic space configuration,offering enhanced stability and impact *** frame-type structure achieves a lightweight ***,we establish a single-objective optimization model for the connecting rod dimensions and apply a genetic algorithm(GA)for their *** also propose a trajectory-fitting calibration theory based on the robotic arm's special configuration and complete its movement accuracy calibration using a laser *** calibration method reduces the robotic arm's motion error by 71%,achieving an absolute positioning accuracy better than 3.5 mm,which meets the requirements for autonomous aerial *** summary,this research presents a hybrid robotic arm that meets automatic docking requirements,offering a new approach to autonomous aerial refueling.

关键词： Autonomous aerial refueling Conical kinematic space configuration Optimization of structural design Calibration method

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A Bionic Starfish Adsorption Crawling Soft Robot

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Journal of Bionic engineering 2024年第1期21卷 149-165页

作者： Xiangang Huang Chenghao Zhang Wenqi Feng Xiangye Zhang Deyuan Zhang Yanqiang Liu Institute of Bionic and Micro-Nano Systems School of Mechanical Engineering and AutomationBeihang UniversityBeijing 100191China

A variety of soft wall-climbing robots have been developed that can move in certain *** of these soft robots can only move on conventional surfaces and lack adaptability to complex *** the adaptability of soft robots on complex surfaces is still a challenging *** this end,we study the layered structure of the starfish tube foot and the valve flap structure in the water vascular system,and use an ultrasonic stress detector to study the stiffness distribution of the arm *** by the motion of the starfish,we present a bionic soft wall-climbing robot,which is driven by two groups of pneumatic feet and achieves body bending through active adaptation *** design the structure of the foot to flex to provide driving force,and there are suction cups at the end of the foot to provide *** soft foot has a simple structure design,adapts to a variety of surfaces,and does not damage the surface of the *** stiffness layers achieve stiffness changes by the principle of line *** Central Pattern Generator theory is introduced to coordinately control the multiple feet of the *** experiments,we verify the adaptability of the soft robot to curved *** research may provide a reference for the design and development of crawling soft robots on complex surfaces.

关键词： Starfish Tube foot Biomimetic robot Soft robot Climbing robot

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