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Microanalysis of a ductile iron by microchip laser-induced breakdown spectroscopy

Plasma Science and Technology 2021年第10期23卷 179-185页

作者： Wei Wang Lanxiang Sun Peng Zhang Liming Zheng Lifeng Qi Jinchi Wang State Key Laboratory of Robotics Shenyang Institute of AutomationChinese Academy of SciencesShenyang 110016People’s Republic of China Key Laboratory of Networked Control System Shenyang Institute of AutomationChinese Academy of SciencesShenyang 110016People's Republic of China Institutes for Robotics and Intelligent Manufacturing Chinese Academy of SciencesShenyang 110169People’s Republic of China University of Chinese Academy of Sciences Beijing 100049People's Republic of China

Laser beams with ns pulse width are generally employed as an excitation source in the process of detecting inclusions and elemental segregation on a workpiece surface by microanalysis of the laser-induced breakdown *** addition,the ablation crater interval of laser sampling on the sample surface is generally 20μm or *** is difficult to detect the morphology of inclusions smaller than 50μm in diameter and the micro-segregation of ***,in this work,when the laser ablation crater is 10μm and the sampling resolution of the laser on the sample surface is 5μm,the morphology and distribution of spherical inclusions(20–60μm)in ductile iron can be detected according to the difference of the Fe spectrum on the Fe matrix and the spheroidal ***,the distribution of micro-segregation of Mg and Ti elements in ductile iron was also studied.

关键词： micro-laser-induced breakdown spectroscopy micro-LIBS mapping inclusion segregation ductile iron

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An Origami-Based Miniature Jumping Robot with Adjustable Jumping Trajectory and Enhanced Intermittent Jumps

An Origami-Based Miniature Jumping Robot with Adjustable Jum...

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IEEE/RSJ International Conference on Intelligent Robots and systems (IROS)

作者： Zhipeng Xiong Lingqi Tang Longlong Hu Songlin Yang Xiaojun Yang Yao Li Bing Li School of Mechanical Engineering and Automation Harbin Institute of Technology Shenzhen China Guangdong Key Laboratory of Intelligent Morphing Mechanisms and Adaptive Robotics Harbin Institute of Technology Shenzhen China State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin China

A small-scale jumping robot can reach obstacles much larger than its size. It is important for a jumping robot to perform intermittent jumps to cross through rough terrains. However, the limitations of conventional structures hinder the further integration of functions to a miniature (sub-50 g) jumping robot. No sub-50 g jumpers could perform intermittent jumps with adjustable jumping trajectories. In this work, we proposed an origami-based miniature jumper, which performed intermittent jumps with adjustable omni-directional trajectories. The intermittent jumps were achieved by the jumping and self-righting mechanisms, which were actuated by a single motor. The clockwise and counterclockwise rotation of the motor actuated the loading, self-righting and triggering process, respectively. The jumping height was adjustable by adjusting the rotation angle of the motor. Meanwhile, the take-off pitch & yaw angle adjustment methods were integrated into the robot. Therefore, we demonstrated a 9 cm, 13.5 g prototype with functions of re-loading, self-righting, jumping height adjustment and take-off pitch & yaw angle adjustment. The robot could adjust jumping height from 16 to 34 cm and self-right for the next jump. The results revealed that our robot could jump across different obstacles with different scales and directions. The mobility was greatly increased compared with other miniature jumping robots.

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Analysis of normal force of wheel-sand interaction for planetary rovers with active suspension*

Analysis of normal force of wheel-sand interaction for plane...

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IEEE International Conference on robotics and Biomimetics

作者： Zhengyin Wang Huaiguang Yang Liang Ding Qingning Lan Haibo Gao Zdravko Terze Zongquan Deng State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin China Faculty of Mechanical Engineering and Naval Architecture University of Zagreb Zagreb Croatia

The planetary rover with active suspension can climb steeper slopes and cross bigger obstacles in a wheel-step motion mode, which enables the planetary rover to perform more complex exploration tasks. However, wheel-step motion requires coordinated movement of the suspension and the wheels: the suspension can determine the wheel's sinkage depth and translation speed. Matching up with the wheel rotation speed can actively construct the slip ratio. The forces exerted on the wheels by sand during this process are a key index for motion control. This poses new challenges to existing wheel-sand interaction models. In this paper, dynamic normal force tests are carried out. The dynamic variation of wheel normal force with slip ratio is investigated at different sinkage depths. It is found that the normal force exerted on the wheel increases firstly and then decreases with the slip ratio, and reaches the maximum value near s=0. The distributed stresses of the wheel were analysed by discrete element method (DEM) simulation, and the phenomenon of the distribution stress reconstruction of the wheel is found. Further, by analyzing the local particles in contact with the wheel, it is found that the particle movement direction and morphology vary with slip ratio. The analysis of the wheel’s normal force and the granular material variation with slip ratio provides the basis for establishing a physics-based wheel-sand interaction model.

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Decoding Discrete Gestures Across Different Arm Positions Based on Multimodal Fusion Strategy 16th

Decoding Discrete Gestures Across Different Arm Positions Ba...

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16th International Conference on Intelligent robotics and Applications, ICIRA 2023

作者： Li, Yunzhe Yin, Zongtian Zhang, Ting Meng, Jianjun School of Mechanical Engineering Shanghai Jiao Tong University 800 Dongchuan Road Shanghai China Robotics and Microsystems Center College of Mechanical and Electrical Engineering Soochow University Suzhou China State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong University 800 Dongchuan Road Shanghai China

ISBN: (纸本)9789819964857

Decoding human motion intentions is critical for prosthetic control, where gesture recognition remains a research focus. However, the decoding accuracy of gestures is affected by multiple factors, resulting in poor robustness in practical applications. Variation in arm positions can significantly decrease the accuracy of gesture recognition, negatively impacting the performance of human-machine interfaces (HMIs). We developed a multimodal HMI system that has the potential to improve the robustness of gesture recognition significantly. This multimodal HMI system synchronously acquired surface electromyography (sEMG), A-mode ultrasound, and inertial measurement unit (IMU) signals and has a miniaturized signal processing module to be integrated into a prosthetic hand socket. We conducted an offline experiment on 11 subjects to investigate the discrete recognition of 10 hand gestures across three different arm positions. The results demonstrate that the multimodal fusion approach using the proposed cascaded classifiers has advantages in gesture recognition across different arm positions. The LDA classifier's best recognition accuracy was 97.08% ± 1.90%, outperforming the single modalities significantly. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023.

关键词： Gesture recognition

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Enveloping grasp planning of a three-fingered deployable metamorphic robotic grasper

Enveloping grasp planning of a three-fingered deployable met...

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IEEE International Conference on Cyborg and Bionic systems (CBS)

作者： Changqing Gao Yang Zhang Hong Lei Xi Kang Peng Xu Bing Li School of Mechanical Engineering and Automation Harbin Institute of Technology Shenzhen China State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin China

This paper takes a three-fingered deployable metamorphic robotic grasper as the studied object and presents a novel enveloping grasp planning method, by which the robotic grasper can grasp objects with different sizes and shapes more effectively and stably. Firstly, the mechanism design and key performances of the robotic grasper are briefly introduced. Secondly, the static analysis of the grasping motion process is conducted and the factors affecting static equilibrium are also analyzed, based on which the mathematical model of static equilibrium is established, and the relationship between grasping force and grasping posture is obtained. Then, an optimization model of static enveloping grasp with the grasping angle as the variable is proposed, by which the best grasping posture can be obtained. Thirdly, to prove the effectiveness of the proposed enveloping grasp planning method, a group of grasping simulations is performed and the results show that this method is feasible and reliable.

关键词： Shape Biological system modeling Force Grasping Static analysis Mathematical models Planning

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FMRT: Learning Accurate Feature Matching with Reconciliatory Transformer

arXiv

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arXiv 2023年

作者： Zhang, Xinyu Wang, Li Jiang, Zhiqiang Dai, Kun Xie, Tao Yang, Lei Yu, Wenhao Shen, Yang Li, Jun The School of Vehicle and Mobility Tsinghua University Beijing100084 China State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin150006 China

Local Feature Matching, an essential component of several computer vision tasks (e.g., structure from motion and visual localization), has been effectively settled by Transformer-based methods. However, these methods only integrate long-range context information among keypoints with a fixed receptive field, which constrains the network from reconciling the importance of features with different receptive fields to realize complete image perception, hence limiting the matching accuracy. In addition, these methods utilize a conventional handcrafted encoding approach to integrate the positional information of keypoints into the visual descriptors, which limits the capability of the network to extract reliable positional encoding message. In this study, we propose Feature Matching with Reconciliatory Transformer (FMRT), a novel Transformer-based detector-free method that reconciles different features with multiple receptive fields adaptively and utilizes parallel networks to realize reliable positional encoding. Specifically, FMRT proposes a dedicated Reconciliatory Transformer (RecFormer) that consists of a Global Perception Attention Layer (GPAL) to extract visual descriptors with different receptive fields and integrate global context information under various scales, Perception Weight Layer (PWL) to measure the importance of various receptive fields adaptively, and Local Perception Feed-forward Network (LPFFN) to extract deep aggregated multi-scale local feature representation. Besides, we introduce a novel Axis-Wise Position Encoder (AWPE) that perceives positional encoding as two independent keypoints encoding tasks along the row and column dimensions and utilizes two parallel network branches to decouple the X- and Y -coordinate information of keypoints, so that boosting the capability of the network to model position information for different images. Extensive experiments demonstrate that FMRT yields extraordinary performance on multiple benchmarks, including pos

关键词： Encoding (symbols)

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Design and Experimental Validation of Sealing Assembly for Lunar Regolith Volatile Extraction Heating Furnace

Design and Experimental Validation of Sealing Assembly for L...

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2023 IEEE International Conference on robotics and Biomimetics, ROBIO 2023

作者： Zhang, Hongan Tang, Junyue Wang, Yinchao Lu, Zixiao Wang, Bo Cao, Miaoyan Jiang, Shengyuan Yanshan University Mechanical Engineering Qinhuangdao China Harbin Institute of Technology State Key Laboratory of Robotics and System Harbin China Shenyang Aerospace University Mechatronics Institute Shenyang China Chinese Academy of Science National Center for Nanoscience and Technlogy Beijing China China Academy of Space Technology Beijing China

ISBN: (纸本)9798350325706

A lunar regolith in-situ analysis payload deploying a mass spectrometer is proposed to exactly detect the water ice of the South Pole of the moon for China future lunar exploration missions. In order to realize the goal, an airtight heating furnace for volatile extraction from lunar regolith is desired. In this paper, sealing methods for lunar regolith volatile in heating furnace to future proposed in-situ sampling and analysis of lunar samples were investigated based on power requirements, furnace closing accuracy requirements, dust tolerance and operation in the Lunar environment. Methods implemented include a balanced metal hollow ring seal, a double channel ferrule tab ring radial seal and a spring energized seal. Comparing the performance of sealing methods under the above conditions, a spring energized seal is selected as the heating furnace seal. The materials and structure of the seal are designed based on the rigidity requirements, leakage rate requirements and working environment requirements. In order to test the sealing performance of seals after repeated sealing in high and low temperature environments, a seal leak detection system was designed. The test results indicate that the seal can meet the sealing performance requirements after repeated sealing at various temperatures. © 2023 IEEE.

关键词： Dust tolerance Leakage rate Lunar environment Repeated sealing Spring energized seal

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Encoding-Based Fusion Estimation for Multi-Sensor systems: Applications to Target Tracking

Encoding-Based Fusion Estimation for Multi-Sensor Systems: A...

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Youth Academic Annual Conference of Chinese Association of Automation (YAC)

作者： Kaiqun Zhu Qirong Tang Pengcheng Zhang State Key Laboratory of Internet of Things for Smart City University of Macau Macau China Laboratory of Robotics and Multibody System Tongji University Shanghai China School of Mechatronic Engineering and Automation Shanghai University Shanghai China

ISBN: (数字)9798350379228

ISBN: (纸本)9798350390780

This paper is concerned with the robust set-membership fusion estimation problem for multi-sensor systems under the influence of uncertain parameters and unknown-but-bounded noises. The sensor nodes and the remote fusion estimator are connected through bandwidth-constrained communication networks. To address this challenge, a dynamic encoding-based data compression mechanism is introduced, enabling the data to be efficiently encoded using a reduced number of bits. By thoroughly analyzing the impact of uncertain parameters, unknown-but-bounded noises, and data distortions on estimation performance, sufficient conditions are derived to ensure that the estimation error remains within the bounded ellipsoidal set. Moreover, the weight parameters are calculated by solving constrained optimization problems. Finally, the effectiveness of the proposed estimation algorithm is verified through a maneuvering target tracking scenario.

关键词： Sufficient conditions Estimation error Target tracking Noise Data compression Set theory Distortion

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Unified Vibration Suppression and Compliance Control for Flexible Joint Robot

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Transactions of Nanjing University of Aeronautics and Astronautics 2021年第3期38卷 361-372页

作者： CUI Shipeng SUN Yongjun LIU Yiwei LIU Hong State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001P.R.China

An adaptive control scheme is presented,which can simultaneously realize vibration suppression and compliance control for flexible joint robot(FJR).The proposed control scheme provides a unified formulation for both vibration suppression mode,where FJR tracks the desired position with little vibration,and compliance mode,in which FJR presents *** of designing multiple controllers and switching between them,both modes are integrated into a single controller,and the transition between two modes is smooth and *** stability of the closed-loop system is theoretically proven via the Lyapunov method,with the considering the dynamics uncertainties in both link side and motor *** results are presented to illustrate good performances of the proposed control scheme.

关键词： adaptive control scheme vibration suppression compliance flexible joint robot(FJR) stability

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Reliability Design of Manipulator Joint for China Space Station 2

Reliability Design of Manipulator Joint for China Space Stat...

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2nd International Conference on Artificial Intelligence, Automation, and High-Performance Computing, AIAHPC 2022

作者： Li, Delun Zhu, Chao Zhang, Yun Bai, Mei Huang, Zhipeng Xie, Zongwu Liu, Teng Fu, Hao State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin150001 China Beijing Key Laboratory of Intelligent Space Robotic Systems Technology and Applications Beijing Institute of Spacecraft System Engineering CAST Beijing100094 China Beijing Satellite Manufacturing Co. Ltd. Beijing100094 China Beijing Institute of Space Environment Engineering Beijing100094 China

ISBN: (纸本)9781510657717

The TianHe manipulator is responsible for major tasks such as China Space Station construction, operation, and supporting astronaut's extravehicular operations. The joint is the direct execution part of the manipulator to realize flexible movement, and it is the key component to ensure the core functions and performance of the China Space Station manipulator, The composition of the joint is complex, and the experience of its reliability design is very poor. So the research of reliability design method for the joint is of great significance. Starting from the joint reliability design method, this paper uses various methods such as redundant design, margin design, and environmental adaptability design to complete the joint reliability design comprehensively. The ideas and methods for reliability design for the joint of the China Space Station manipulator introduced in this paper have important reference value for the reliability design for the space complicated electromechanical products. © 2022 SPIE. All rights reserved.

关键词： Space stations

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