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Damage evolution and removal behaviors of GaN crystals involved in double-grits grinding

International Journal of Extreme Manufacturing 2024年第2期6卷 469-484页

作者： Chen Li Yuxiu Hu Zongze Wei Chongjun Wu Yunfeng Peng Feihu Zhang Yanquan Geng State Key Laboratory of Robotics and System(HIT) Harbin Institute of TechnologyHarbin 150001People’s Republic of China Key Laboratory of Microsystems and Microstructures Manufacturing(HIT) Harbin Institute of TechnologyHarbin 150001People’s Republic of China College of Mechanical Engineering Donghua UniversityShanghai 201620People’s Republic of China Department of Mechanical and Electrical Engineering Xiamen UniversityXiamen 361005People’s Republic of China

Elucidating the complex interactions between the work material and abrasives during grinding of gallium nitride(GaN)single crystals is an active and challenging research *** this study,molecular dynamics simulations were performed on double-grits interacted grinding of GaN crystals;and the grinding force,coefficient of friction,stress distribution,plastic damage behaviors,and abrasive damage were systematically *** results demonstrated that the interacted distance in both radial and transverse directions achieved better grinding quality than that in only one *** grinding force,grinding induced stress,subsurface damage depth,and abrasive wear increase as the transverse interacted distance ***,there was no clear correlation between the interaction distance and the number of atoms in the phase transition and dislocation *** interacted distances between abrasives can decrease grinding force,coefficient of friction,grinding induced stress,subsurface damage depth,and abrasive wear during the grinding *** results of grinding tests combined with cross-sectional transmission electron micrographs validated the simulated damage results,*** atoms,high-pressure phase transition,dislocations,stacking faults,and lattice *** results of this study will deepen our understanding of damage accumulation and material removal resulting from coupling between abrasives during grinding and can be used to develop a feasible approach to the wheel design of ordered abrasives.

关键词： grinding double-grits molecular dynamics damage material removal gallium nitride

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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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2023 IEEE International Conference on robotics and Biomimetics, ROBIO 2023

作者： Wang, Zhengyin Yang, Huaiguang Ding, Liang Lan, Qingning Gao, Haibo Terze, Zdravko Deng, Zongquan Harbin Institute of Technology State Key Laboratory of Robotics and System Harbin150001 China University of Zagreb Faculty of Mechanical Engineering and Naval Architecture Zagreb10000 Croatia

ISBN: (纸本)9798350325706

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. © 2023 IEEE.

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Simulation study on the error of the double parallel-joints coordinate measuring machine

Simulation study on the error of the double parallel-joints ...

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International Workshop on Intelligent systems and Applications

作者： Yu, Lingtao Shuai, Rongbiao Zhao, Jilang Wu, Guoliang Xia, Guisuo Lai, Zhihua Wu, Haiyan State Key Laboratory of Robotics and System HIT Harbin China School of Mechanical and Electrical Engineering Harbin Engineering University Harbin China Jiujiang Precision Measuring Technology Research Institute Jiujiang China

ISBN: (纸本)9781424498574

The double parallel-joints CMM is a new coordinate measuring machine that between the tradion coordinate measuring machine and the multi-joint coordinate measuring machine. To further study of the double parallel-joints CMM , it is necessary to study on the error model of the measuring machine. The kinematics model is constructed by the D-H method and the error model for the double parallel-joints CMM is constructed too. The SimMechanics institutions model and the M-function model verifies that the theoretical analysis is ture ,by the simulation. to verify the correctness of the error model, laying the groundwork for further theoretical research. The theoretic foundation is made for the further study of The double parallel-joints CMM. © 2011 IEEE.

关键词： MATLAB

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A novel method of biped walking pattern generation with predetermined knee joint motion

A novel method of biped walking pattern generation with pred...

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2004 IEEE/RSJ International Conference on Intelligent Robots and systems (IROS)

作者： Ogura, Yu Kataoka, Teruo Shimomura, Kazushi Lim, Hun-Ok Takanishi, Atsuo Grad. Sch. of Sci. and Engineering Waseda University Tokyo Japan Dept. of System Design Engineering Kanagawa Institute of Technology Atsugi Japan Department of Mechanical Engineering Humanoid Robotics Institute Waseda University Tokyo Japan

ISBN: (纸本)0780384636

This paper describes a method of motion pattern generation for biped humanoid robot to walk like humans or walk with various kind of motions. To realize biped walking avoiding singularity at stretching leg, pattern generation uses predetermined knee joint trajectories. Reduction of DOF by predetermination is complemented by waist motion. The effectiveness of generated dynamic walking patterns is confirmed by using a 16-DOF biped robot WABIAN-2/LL.

关键词： Biped locomotion

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A pose measurement system for optical precision operation

A pose measurement system for optical precision operation

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作者： Ma, Li Rong, Weibin Ouyang, Hangkong He, Zhengfeng Sun, Lining Department of Precise Mechanical Engineering School of Mechanical and Electronic Engineering and Automation Shanghai University Shanghai 200072 China State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin 150080 China

A new 3-DOF pose precision measurement system based on linear variable differential transformer (LVDT) is developed, built and tested. The system is mainly composed of four LVDTs of symmetrical distribution, which is used to detect the pose relations between a spherical mirror and a resonantor in an optical assembly process. Motion pose of the spherical mirror controlled by an optical assembly robot is formulated according to their geometrical relationship. A LVDT processing circuit using integrated signal conditioning chip AD598 is designed as the control system of pose measurement. Calibration experiments illustrate that the LVDT possesses well static and dynamic characteristics. A PID algorithm is used to improve the adjusting efficiency. Experimental results show that the pose measurement system with maximum angle error of 10" and maximum distance error of 0.5 μm can complete pose adjustment between the spherical mirror and the resonator in 25 seconds, which demonstrate the effectiveness of the proposed method for pose measurement. Copyright © 2011 American Scientific Publishers All rights reserved.

关键词： Mirrors

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Design and safety control of a high-payload nursing robotic arm with tactile skin

Design and safety control of a high-payload nursing robotic ...

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2019 IEEE International Conference on robotics and Biomimetics, ROBIO 2019

作者： Wu, Jiahao Song, Yanshu Huang, Hailin Liu, Fei Chen, Junan Li, Bing Harbin Institute of Technology School of Mechanical Engineering and Technology Shenzhen518055 China Harbin Institute of Technology School of Electronic and Information Engineering Shenzhen518055 China Harbin Institute of Technology State Key Laboratory of Robotics and System Harbin150001 China

ISBN: (纸本)9781728163215

Service robots are being increasingly used to replace human beings in carrying out various sophisticated, heavy and even dangerous tasks. In order to solve the problem of labor shortage in the medical and nursing industry, this paper proposes a novel high-payload robotic arm for nursing tasks, which can help caregivers to lift and transfer patients. Firstly, we simulate and analyze the specific nursing tasks and application scenarios, and determine its kinematics configuration and load capacity parameters of each joint. Then we design and fabricate the modular and low flexibility robotic joints for the prototype. To avoid the occurrence of safety accidents while lifting patients, we design a new kind of tactile skin based on the resistance characteristic of varistor materials, using which a safety control algorithm is proposed. Experiments show that it can meet the requirements of load capacity and position control accuracy, and the proposed safety control method can effectively avoid many dangerous situations. © 2019 IEEE.

关键词： Nursing

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Combine Neural Radiance Fields in Different Reference Coordinates

Combine Neural Radiance Fields in Different Reference Coordi...

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2023 China Automation Congress, CAC 2023

作者： Zhang, Weili Li, Zhongheng Guo, Yu Wang, Fei Institute of Artificial Intelligence and Robotics Xi'An Jiaotong University Xi'an China Beijing Institute of Spacecraft System Engineering Beijing Key Laboratory of Intelligent Space Robotic Systems Technology and Applications Beijing China

ISBN: (纸本)9798350303759

Neural Radiance Fields (NeRF) leverage deep learning networks to restore high-quality implicit representations of 3D scenes from 2D images, surpassing traditional texture mapping in rendering quality. Typically, reconstructed images by NeRF exist in a reference coordinate system, necessitating consideration of each surface's information in a single shot. Overlapping parts in adjacent images are addressed by obtaining the camera pose through sparse COLMAP reconstruction. However, occluded regions, caused by contact with support surfaces, pose challenges for complete reconstruction. To address this, we propose a scene fusion algorithm based on NeRF, facilitating the amalgamation of neural radiance fields under different reference coordinate systems. This reduces data requirements and shooting conditions, enhancing the implicit 3D reconstruction of real objects. By estimating the translation and rotation relationship between image capture angles and the NeRF model, we fuse neural radiance fields in distinct reference coordinate systems, completing object surface information. Evaluation is conducted on both NeRF synthetic dataset and real objects. © 2023 IEEE.

关键词： Cameras

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Fast and accurate humanoid robot navigation guided by stereovision

Fast and accurate humanoid robot navigation guided by stereo...

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2009 IEEE International Conference on Mechatronics and Automation, ICMA 2009

作者： Guodong, Chen Xie, Ming Xia, Zeyang Sun, Lining Ji, Junhong Du, Zhijiang Lei, Wang State Key Laboratory of Robotics and System Harbin Institute of Technology China Nanyang Technological University Singapore School of Mechanical and Aerospace Engineering Nanyang Technological University Singapore Harbin Institute of Technological China

ISBN: (纸本)9781424426935

Stair-climbing and moving object grasping both require high precision information feedback of the feature coordinate. This manuscript mainly describes how to process the information acquired from the stereovision system in a fast and accurate way and how to use the data to compensate the progressive error caused by the humanoid robot. From camera calibration to image processing to stereo match, every step in the whole vision information processing process plays an important role in getting high precision. Less time consuming can make the robot adapt to the changes of environment quickly, especially in dynamic environment. In this paper, two humanoid robot common tasks are chosen as experiments to verify the effectiveness of the proposed methods. Stair climbing experiment verifies the high precision in long distances and also by using the image information to compensate the progressive error caused by long distance walking and moving object grasping experiment verifies the less time consuming. ©2009 IEEE.

关键词： Anthropomorphic robots

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Assembly sequence planning based on assembly knowledge database

Assembly sequence planning based on assembly knowledge datab...

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2nd International Conference on Information engineering and Applications, IEA 2012

作者： Li, Rong Tian, Ying School of Automobile and Traffic Engineering Heilongjiang Institute of Technology Harbin 150050 China State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin 150050 China School of Mechanical Engineering Tianjin University Tianjin 300072 China

ISBN: (纸本)9781447148494

An assembly sequence planning method based on assembly knowledge is put forward. Three types of the assembly knowledge were defined, and the knowledge database was established, which include products' part designing knowledge, joining knowledge, and assembly rule knowledge. According to all of the knowledge, assembly model was building and simplified. Supported by above knowledge assembly model, by firing the state matrix, all the feasible sequence can be obtained. Then, the sequences of the joining were acquired from the knowledge database, which were insert into the feasible sequence, and the assembly sequence were obtained. Finally, a simple case is provided to illustrate the effectiveness of the proposed method. © 2013 Springer-Verlag.

关键词： Petri nets

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Lower Limb Rehabilitation Motion Angle Measurement Based On Deep Learning YOLOv3 Model 2

Lower Limb Rehabilitation Motion Angle Measurement Based On ...

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2021 2nd International Conference on Machine Learning and Computer Application, ICMLCA 2021

作者： Yang, Yunlong Wang, Liancheng Yao, Yufeng He, Chenxi Yin, Hesheng Weihai Furui Robotics Co. Ltd Weihai China Tianzhi Institute of Innovation and Technology Weihai Economic and Technological Development Zone Weihai China Weihai China State Key Laboratory of Robotics Harbin Institute of Technology System Department of Mechanical Engineering Harbin China

ISBN: (纸本)9783800757398

The aging of the population and the high incidence of hemiplegia have led to an increasing demand for easy-to-use rehabilitation training. The feedback sensing system which can measure and analyze the lower limb rehabilitation motions is highly significant for improving the rehabilitation outcome. Computer vision-based human motion angle measurement has attracted significant interest. This study aims to measure and analyze the lower limb motion angle in the sagittal plane with a single RGB camera. This paper proposes a method for extracting and monitoring of the lower limb marker points based on YOLOv3 and DarkNet-53 convolutional neural networks, and optimizes the pixel coordinates of the target point based on Kalman. The measurement accuracy of the proposed method is tested by JACO robotic arm, and the test shows that the standard deviation (SD) of the measurement is less than 0.5°. © VDE VERLAG GMBH · Berlin · Offenbach.

关键词： Neural networks

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