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Configuration Design of an Under-Actuated Robotic Hand Based on Maximum Grasping Space

Chinese Journal of Mechanical Engineering 2018年第2期31卷 45-53页

作者： Shang-Ling Qiao Rong-Qiang Liu Hong-Wei Guo Yu-Xuan Liu Zong-Quan Deng State Key Laboratory of Robotics and System Harbin Institute of Technology College of International Cooperative Education Harbin Engineering University

Capture is a key component for on?orbit service and space debris clean. The current research of capture on?orbit focuses on using special capture devices or full?actuated space arms to capture cooperative targets. However, the structures of current capture devices are complex, and both space debris and abandoned spacecraft are non?cooperative targets. To capture non?cooperative targets in space, a lightweight, less driven under?actuated robotic hand is proposed in this paper, which composed by tendon?pulley transmission and double?stage mechanisms, and always driven by only one motor in process of closing finger. Because of the expandability, general grasping model is constructed. The equivalent joint driving forces and general grasping force are analyzed based on the model and the principle of virtual work. Which reveal the relationship among tendon driving force, joint driving forces and grasping force. In order to configure the number of knuckles of finger, a new analysis method which takes the maximum grasping space into account, is proposed. Supposing the maximum grasped object is an envelope circle with diameter of 2.5m. In the condition, a finger grasping maximum envelope circle with different knuckles is modeled. And the finger lengths with corresponding knuckles are calculated out. The finger length which consists of three knuckles is the shortest among under?actuated fingers consists of not more than five knuckles. Finally, the principle prototype and prototype robotic hand which consists of two dingers are designed and assembled. Experiments indicate that the under?actuated robotic hand can satisfy the grasp requirements.

关键词： Under?actuated robotic hand Tendon?pulley transmission Grasping space Configuration design

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A legged device based on active buffering for probe landing on micro-gravitational asteroid

A legged device based on active buffering for probe landing ...

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2019 IEEE International Conference on robotics and Biomimetics, ROBIO 2019

作者： Yin, Canhui Shen, Yilin Zhang, Xiaolin Guo, Fan Quan, Qiquan Tang, Dewei Deng, Zongquan Harbin Institute of Technology State Key Laboratory of Robotics and System Harbin Heilongjiang Province China Beijing Institute of Spacecraft System Engineering Beijing China China Academy of Space Technology Beijing China

ISBN: (纸本)9781728163215

The landing of the probe on the asteroid surface provides the technical basis for in-situ exploration and sampling return and promotes to maximize the value of the probe. The micro-gravitation and the uncertainty in topography and geology on the asteroid surface pose challenges to the landing of the probe. To develop the asteroid landing technology, the legged landing device of asteroid probe based on active buffering mode is studied in this paper. The landing device adopts a three-legged structure to possess higher adaptability to the surface topography of asteroids and get the light and simple configuration. Besides, a buffering unit is designed based on the active mode of the damping motor which has obvious advantages in self-adaptability and autonomy. Through the comparison of various schemes, the slider-legged landing device is determined and designed in detail. On this basis, the co-simulation of the probe landing on the asteroid surface is completed, which shows the satisfaction of this device to reliability and efficiency. Finally, a prototype of the landing device is constructed and the micro-gravitational simulated test platform is developed to implement the landing buffering test of asteroid probe. The test results validate the performance of the landing device. © 2019 IEEE.

关键词： Damping

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Automatic detection of circulating tumor cells with very deep residual networks 19

Automatic detection of circulating tumor cells with very dee...

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9th International Conference on Biomedical Engineering and Technology, ICBET 2019

作者： Li, Bin Ge, Yunhao Zhao, Yanzheng Yan, Weixin Robotics Institute Shanghai Jiao Tong University Shanghai China State Key Lab of Mechanical System Vibration Shanghai Jiao Tong University Shanghai China

ISBN: (纸本)9781450361309

Automatic detection of circulating tumor cells (CTCs) in microscopic images is a very challenging task due to the variable artificial and environmental factors, such as inconsistency of light intensity and staining, cell adhesion, multiple impurities and so on. In order to meet these challenges, we propose a novel deep multiscale residual network (DMRN) for CTCs detection. Compared with existing methods either low-level hand-crafted features or CNNs with shallower architectures, our deep networks can acquire more discriminative features for more accurate detection. To train very deep networks more efficiently, we propose a set of schemes to ensure effective training and learning under limited training data. First, we apply the residual learning to generate more discriminative features and overcome the overfitting problem when a network goes to deeper. Then, a fully residual convolutional network (FRCN) is proposed to produce the prediction maps of CTCs. Finally, we propose to integrate multi-scale contextual information in proposed FRCN and fuse these prediction maps both global and local features of CTCs, making the prediction more accurate and robust. We built three DMRN models to study the impact of network depth on model performance. Each model was tested on our own dataset containing complex jamming information. The DRMN-50 model which has a depth of 50 layers performs best among three models with Jaccard-index of 0.810 (with a pixel accuracy of 99.8% as a reference index) and its performance outperform other existing state-of-art methods such as U-Net in other domain. The result also depicts the accurate and robust performance of proposed method in complex environment. © 2019 Association for Computing Machinery.

关键词： Forecasting

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Grip Force Perception Based on dAENN for Minimally Invasive Surgery Robot

Grip Force Perception Based on dAENN for Minimally Invasive ...

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2019 IEEE International Conference on robotics and Biomimetics, ROBIO 2019

作者： Guo, Yongchen Pan, Bo Fu, Yili Meng, Max Q.-H. Harbin Institute of Technology State Key Laboratory of Robotics and System Harbin Heilongjiang China Chinese University of Hong Kong Department of Electronic Engineering Hong Kong

ISBN: (纸本)9781728163215

Although robot assisted minimally invasive surgery brings the gospel to patients, force perception is gone. Among all the contact forces during surgery, the instrument grip force plays the most important role. In this paper, a grip force perception method based on denoising AutoEncoder Neural Network (dAENN) is proposed. The method utilizes sensor data including encoder readings and motor current over a time window as the input of dAENN for sufficient information. An Artificial Neural Network (ANN) is then introduced as a machine learning tool to learn the nonlinear mapping between the compact features and grip force labels. Feature extraction is first introduced into grip force perception problem in this paper. Experiment results shows adequate expressive capability of the extracted coding as well as the superior grip force perception performance over several popular data-based methods under the same dataset. © 2019 IEEE.

关键词： Neural networks

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Design and analysis of a cable-driven multistage orderly deployable/retractable space telescopic boom

Design and analysis of a cable-driven multistage orderly dep...

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作者： Zhao, Chong Guo, Hongwei Liu, Rongqiang Deng, Zongquan Li, Bing State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin150080 China Shenzhen Graduate School Harbin Institute of Technology Shenzhen518055 China

In order to meet the requirement of spacecraft instrument’s repeated deployment, this paper presents a novel cable-driven space telescopic boom (STB) which can be orderly deployable/retractable. First, a novel metamorphic mechanism cell (MMC) which can realize locking, unlocking and interlocking with other cells is proposed, and the metamorphic principle, degree of freedom and motion condition of this type of cells are analyzed. Second, the novel 9-tube cable-driven STB is proposed based on MMCs. Modal analysis of the STB is performed using ANSYS WROKBENCH to verify that the STB has good rigidity. And the kinematics simulation of the STB is conducted using ADAMS software to verify that the deploying and locking functions. © 2019, Springer Nature Switzerland AG.

关键词： Modal analysis

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Bionic Knee Joint Structure and Motion Analysis of a Lower Extremity Exoskeleton

Bionic Knee Joint Structure and Motion Analysis of a Lower E...

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International Conference on robotics and Automation Sciences (ICRAS)

作者： Yongfei Xiao Xiangjing Ji Hao Wu Xinpeng Zhai Xiaochun Fu Jie Zhao Institute of Automation Qilu University of Technology (Shandong Academic of Science) Jinan China State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin China

ISBN: (数字)9781728198576

ISBN: (纸本)9781728198583

In order to solve the problem of poor human-machine compliance of wearable lower extremity exoskeleton robots, a modified lower extremity exoskeleton with a four-bar mechanism in the knee joint is proposed and analyzed. The advantages of the four-bar mechanism relative to the traditional two-bar hinge structure are explained by analyzing the physiological characteristics of the human knee joint. In addition, the kinematics of traditional and modified lower extremity exoskeletons are compared. The constraint relationship and motion equations of instantaneous rotating center of the four-bar linkage knee joint are derived. Finally, gait simulations are performed on the two lower extremity exoskeleton models to obtain the position and angle information of the joints. The influence of the four-bar mechanism of bionic knee joint on the lower extremity exoskeleton is described. The simulation results show that the modified lower extremity exoskeleton not only improves the biomimetic performance of knee joint, but also conforms to the characteristics of human gait.

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A Local Dynamic Path Planning Approach for WMRs Based on Fuzzy Dual CHOMP 9

A Local Dynamic Path Planning Approach for WMRs Based on Fuz...

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9th IEEE International Conference on Cyber Technology in Automation, Control and Intelligent systems, CYBER 2019

作者： Li, Zhi Ding, Liang You, Bo Gao, Haibo Mechanical Power Engineering College Harbin University of Science and Technology Harbin China State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin China

ISBN: (纸本)9781728107691

Wheeled mobile robots (WMRs) are widely utilized in exploration tasks on different planets. The path planning technique is required to guide a WMR to a target point or region. A new path planning method in a dynamic environment is proposed. The method improves the original dual Covariant Hamiltonian Optimization for Motion Planning (CHOMP) method by a fuzzy reasoning module and Nonmonotone Gradient Projection Algorithm (NGPA). Thus, this method can achieve low cost paths while maintaining the accessibility of each path nodes. The method to establish local dynamic cost map based on a new velocity-based artificial potential field (VAPF) is proposed as the environment for path planning. Thus, the low cost paths can guide a WMR away from obstacles. Results of the simulations show that the path planning method can dynamically generate a smooth path for a WMR to avoid obstacles. © 2019 IEEE.

关键词： Mobile robots

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Overcoming Van der Waals Forces in reconfigurable nanostructures

arXiv

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arXiv 2022年

作者： Zhang, Wang Wang, Hao Tan, Alvin T.L. Ranganath, Anupama Sargur Zhang, Biao Wang, Hongtao Chan, John You En Ruan, Qifeng Liu, Hailong Ha, Son Tung Wang, Dong Ravikumar, Venkat K. Low, Hong Yee Yang, Joel K.W. Engineering Product Development Singapore University of Technology and Design Singapore487372 Singapore Northwestern Polytechnical University 127 West Youyi Road Xi'An710072 China Institute of Materials Research and Engineering Singapore138634 Singapore Robotics Institute State Key Laboratory of Mechanical System and Vibration School of Mechanical Engineering Shanghai Jiao Tong University Shanghai200240 China Advanced Micro Devices Singapore Pte Ltd Singapore Singapore

Reconfigurable metamaterials1-3 require constituent nanostructures to demonstrate switching of shapes with external stimuli. For generality, such nanostructures would touch and stick to other surfaces in one of its configurations. Yet, a longstanding challenge is in overcoming this stiction caused by Van der Waals forces, which impedes shape recovery. Here, we introduce a stiff yet self-recovering material system based on acrylic acid, and tested it in high-aspect ratio structures, where recovery is weak. This designer material has a storage modulus of ~5.2 GPa at room temperature and ~90 MPa in the rubbery state at 150 ℃, an order of magnitude higher than previous reports. A high-resolution resin for two-photon lithography was developed based on this polymer system, enabling 3D printing of nanopillars with diameters of ~400 nm and aspect ratio as high as ~10. Experimentally, we observed self-recovery as collapsed and touching structures overcome stiction to stand back up. We developed a theoretical model to explain the recoverability of these sub-micron structures. Reconfigurable structural colour prints and holograms were demonstrated, indicating potential applications of the material system as a shape memory polymer suitable for sub-micron reconfigurable metamaterials. Copyright © 2022, The Authors. All rights reserved.

关键词： Van der Waals forces

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Nonequilibrium Effects on Rapid Directional Solidification Microstructures During Additive Manufacturing: A Quantitative Phase Field Study

SSRN

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SSRN 2024年

作者： Li, Leiji Xiao, Fei Li, Zhu He, Shiyu Liu, Yang Cai, Xiaorong Hou, Ruihang Zhou, Ying Zuo, Shungui Zhang, Chongfeng Gao, Jinzhong Shen, Xiaopeng Zhu, Tianchi Gu, Yijia Jin, Xuejun State Key Lab of Metal Matrix Composite School of Materials Science and Engineering Shanghai Jiao Tong University 800 Dong Chuan Road Shanghai200240 China Institute of Medical Robotics Shanghai Jiao Tong University Shanghai200240 China National Key Laboratory of Aerospace Mechanism Aerospace System Engineering Shanghai 3805 Jin Du Road Shanghai201108 China Department of Materials Science and Engineering Missouri University of Science and Technology RollaMO65409 United States National Engineering Research Center of Advanced Magnetic Resonance Technologies for Diagnosis and Therapy School of Materials Science and Engineering Shanghai Jiao Tong University 800 Dong Chuan Road Shanghai200240 China Department of Materials Science and Engineering Graduate School of Engineering Osaka University 2-1 Yamada-oka Osaka Suita565-0871 Japan Shanghai Key Laboratory of Materials Laser Processing and Modification China

Fusion-based metal additive manufacturing (AM) is a technology that builds objects layer by layer, with rapid solidification referring to the quick transition of material from liquid to solid. During this process, solute trapping, a nonequilibrium effect characterized by velocity-dependent partition coefficient, significantly influences microstructure kinetics, morphology, and phase formation. This study utilizes the latest quantitative phase field (PF) model to systematically investigate the solute trapping, solute drag, and their effects on pattern formation during rapid solidification at velocities relevant to AM, in both one and two dimensions. Under different temperature gradients and pulling velocities, we observed that the growth mode transits from planar to cellular to dendritic, then back to cellular, and finally to planar, which is consistent with classic solidification theory. A solidification microstructure selection map is constructed based on PF simulations. Furthermore, we compared primary dendritic/cell spacing calculated by the PF model with theoretical models. The simulated morphologies and arm spacing showed good agreement with experimental observations for Al-4Si and Ti-20Nb alloys during rapid solidification. These results demonstrate the potential of the PF model for predicting and controlling microstructure formation under rapid solidification conditions in the melt pool of AM processes. © 2024, The Authors. All rights reserved.

关键词： Morphology

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270-degree arc-shaped piezoelectric energy converter in uniflow fluid environment 2

270-degree arc-shaped piezoelectric energy converter in unif...

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2nd International Conference on Modeling in Mechanics and Materials

作者： Gong, Ying Shan, Xiaobiao Yang, Zhengbao Xie, Tao State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin 150001 China City University of Hong Kong Tat Chee Avenue Kowloon Hong Kong

Energy harvesting in uniflow fluid environment aims at ambient energy that can be used in water environment for monitor equipment. In this paper, we focus on coupling both bending vibration and torsional vibration to gain better power generation. A novel structure of energy converter(arc-shaped) was designed and manufactured. Meanwhile the influence of vibrator with and without a pelvic fin was tested. Mathematical analyse due to vibration phenomenon and experimental result are reported. The 270-degree arc-shaped ring size piezoelectric ceramic is verified capable of producing an effective voltage over 10 V with the power of 0.5 mW. © Published under licence by IOP Publishing Ltd.

关键词： Energy harvesting

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