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Research Square 2021年

作者： Hu, Xinghao Jia, Jingjing Wang, Yingming Tang, Xintian Fang, Shaoli Wang, Yilun Wang, Jian Baughman, Ray Ding, Jian-Ning The University of Texas Dallas United States Institute of Intelligent Flexible Mechatronics Jiangsu University China State Key Laboratory of Robotics and System Harbin Institute of Technology China Jiangsu University China

Electrothermal carbon nanotube (CNT) yarn muscles can provide large strokes during heating-cooling cycles. However, the slow cooling rate of thermal muscles limit their applications, since large diameter prior-art thermal muscles cannot be rapidly cycled. We here report an ultrafast thermally powered sheath-driven yarn muscle that uses a hybrid CNT sheath and an inexpensive polymer core. Our coiled muscle contracts 14.3% at 1 Hz and 7.3% at 8 Hz in air when powered by a square-wave electrical voltage input. The 70-mm-diameter actuated muscle cools in air to 16℃ from 150℃ within 0.5 s, compared with 6 s for a 65-mm-diameter sheath-run muscle that uses an electrothermally heated CNT core and 9 s for a 78-mm-diameter muscle that uses the sheath material for the entire muscle. An average power density of 12 kW/kg was obtained for a sheath-driven muscle, which is 42 times that for human skeletal muscle. This high performance results since the heating that drives fast actuation cycles is largely restricted to the muscle sheath, and this sheath is in direct contact with ambient temperature air. © 2021, CC BY.

关键词： Carbon nanotubes

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A Spray Path Planning Algorithm based on 3D Point Cloud 3

A Spray Path Planning Algorithm based on 3D Point Cloud

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3rd IEEE Advanced Information Management, Communicates, Electronic and Automation Control Conference, IMCEC 2019

作者： Tong, Ning Kong, Minxiu Xu, Shengrun Harbin Institute of Technology School of Mechatronics Engineering China State Key Laboratory of Robotics and System Harbin China

ISBN: (纸本)9781728105130

Robotic spray path planning for complex surface has always been a challenging problem, especially when it comes to flexible manufacturing system. This paper presents a new method to plan the spray path based on the point cloud obtained by vision sensors. In order to select the direction of slice adaptively, a method based on principal component analysis (PCA) is adopted to calculate the dominant eigenvector of point cloud. The intersection algorithm is also discussed to obtain points for constructing spraying path. The normal vector calculation and sorting problem of slice points are also solved. The experimental results show that the proposed path planning method can automatically generate the spraying path according to the surface of spray target. This method can also be extended to other applications. © 2019 IEEE.

关键词： Principal component analysis

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Design and Experiment of a Compact Cable-Driving Module for Reconfigurable Cable-Driven Parallel Robots

Research Square

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Research Square 2020年

作者： Yuan, Han An, Hao Zhang, Yongqing Xu, Wenfu Shenzhen518055 China State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin150080 China

Cable-driven parallel robots (CDPRs) have the characteristics of reconfigurability, which endows CDPRs with flexible workspace, freely configurable degrees of freedom and various configurations, greatly expanding their range of applications. Modular design provides great convenience and feasibility for the realization of reconfiguration, which is a key issue of reconfiguration research. However, most existing CDPRs have problems of low modularity and low system integration, which brings inconvenience to the realization of reconfiguration. In this paper, a highly integrated and high precision cable-driving module is designed, which can accurately control the length and tension of the cable. In addition, experimental verification is performed. The single-module experiment shows that the module has good ability for cable length and cable tension control. The cable length control error is less than 0.2mm, and the cable tension control error is less than 0.8N. Furthermore, based on the proposed module, a CDPR with 8 cables and 6 degrees of freedom is constructed rapidly. The open-loop tracking error of the robot is measured by laser tracker. Results show that the tracking error is less than 4.5mm and the Root-Mean-Square-Error (RMSE) is 2.1mm. Besides, the compliance control experiment of the robot shows that the tracking error in impedance control mode is less than 2mm, and the RMSE is 0.95mm, and the drag force in teaching mode is less than 2.5N, which demonstrates good follow-up performance. The proposed compact cable-driving module with high precision could be useful for the design and rapid construction of reconfigurable CDPRs. © 2020, CC BY.

关键词： Cables

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Online 4D Ultrasound-Guided Robotic Tracking Enables 3D Ultrasound Localisation Microscopy with Large Tissue Displacements

arXiv

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arXiv 2024年

作者： Yan, Jipeng Tan, Qingyuan Kawara, Shusei Zhu, Jingwen Wang, Bingxue Toulemonde, Matthieu Liu, Honghai Tan, Ying Tang, Meng-Xing Ultrasound Lab for Imaging and Sensing Department of Bioengineering Imperial College London LondonSW7 2AZ United Kingdom the State Key Laboratory of Robotics and Systems Harbin Institute of Technology Harbin150001 China the Department of Bioengineering Imperial College London LondonSW7 2AZ United Kingdom the School of Computing University of Portsmouth PortsmouthPO1 2UP United Kingdom the Department of Mechanical Engineering University of Melbourne ParkvilleVIC3010 Australia

Super-Resolution Ultrasound (SRUS) imaging through localising and tracking microbubbles, also known as Ultrasound Localisation Microscopy (ULM), has demonstrated significant potential for reconstructing microvasculature and flows with sub-diffraction resolution in clinical diagnostics. However, imaging organs with large tissue movements, such as those caused by respiration, presents substantial challenges. Existing methods often require breath holding to maintain accumulation accuracy, which limits data acquisition time and ULM image saturation. To improve image quality in the presence of large tissue movements, this study introduces an approach integrating high-frame-rate ultrasound with online precise robotic probe control. Tested on a microvasculature phantom with translation motions up to 20 mm, twice the aperture size of the matrix array used, our method achieved real-time tracking of the moving phantom and imaging volume rate at 85 Hz, keeping majority of the target volume in the imaging field of view. ULM images of the moving cross channels in the phantom were successfully reconstructed in post-processing, demonstrating the feasibility of super-resolution imaging under large tissue motions. This represents a significant step towards ULM imaging of organs with large motion. © 2024, CC BY-NC-ND.

关键词： Image enhancement

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On Modeling Drilling Load in Lunar Regolith Simulant

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Chinese Journal of Mechanical Engineering 2018年第1期31卷 41-52页

作者： Qi-Quan Quan Chong-Bin Chen Zong-Quan Deng Jun-Yue Tang De-Wei Tang State Key Laboratory of Robotics and System Harbin Institute of Technology

Drilling and coring, as effective ways to obtain lunar regolith along the longitudinal direction, are widely applied in the lunar sampling field. Conventionally, modeling of drill-soil interaction was divided into soil cutting and screw conveyance processes, ignoring the differences in soil mechanical properties between them. To improve the modeling accuracy, a hypothesis that divides the drill-soil interaction into four parts: cuttings screw conveyance, cuttings extruding, cuttings bulldozing, and in situ simulant cutting, is proposed to establish a novel model based on the passive earth pressure theory. An iterative numerical calculation method is developed to predict the drilling loads. A drilling and coring testbed is developed to conduct experimental tests. Drilling experiments indicate that the drilling loads calculated by the proposed model match well the experimental results. The proposed research provides the instructions to adopt a suitable drilling strategy to match the rotary and penetrating motions, to increase the safety and reliability of drilling control in lunar sampling missions.

关键词： Lunar regolith drilling Lunar regolith simulant Drill-simulant interaction Screw conveyance

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Formation mechanism of a smooth, defectfree surface of fused silica optics using rapid CO2 laser polishing

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International Journal of Extreme Manufacturing 2019年第3期1卷 85-95页

作者： Linjie Zhao Jian Cheng Mingjun Chen Xiaodong Yuan Wei Liao Qi Liu Hao Yang Haijun Wang State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001People’s Republic of China Research Center of Laser Fusion China Academy of Engineering PhysicsMianyang 621900People’s Republic of China

Surface defects introduced by conventional mechanical processing methods can induce irreversible damage and reduce the service life of optics applied in high-power *** to mechanical processing,laser polishing with moving beam spot is a noncontact processing method,which is able to form a defect-free *** work aims to explore the mechanism of forming a smooth,defect-free fused silica surface by high-power density laser polishing with coupled multiple *** underlying mechanisms of laser polishing was revealed by numerical simulations and the theoretical results were verified by *** simulated polishing depth and machined surface morphology were in close agreement with the experimental *** obtain the optimized polishing quality,the effects of laser polishing parameters(*** rate,pulse width and polishing times)on the polishing quality were experimentally *** was found that the processing efficiency of fused silica materials by carbon dioxide(CO2)laser polishing could reach 8.68 mm2 s−1,and the surface roughness(Ra)was better than 25 ***,the cracks on pristine fused silica surfaces introduced by initial grinding process were completely removed by laser polishing to achieve a defect-free *** maximum laser polishing rate can reach 3.88μm s−1,much higher than that of the traditional mechanical polishing *** rapid CO2 laser polishing can effectively achieve smooth,defect-free surface,which is of great significance to improve the surface quality of fused silica optics applied in high-power laser facilities.

关键词： laser polishing mechanical processing smooth surface defect-free surface polishing rate

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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...

引用

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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Configuration synthesis of planar folded and common overconstrained spatial rectangular pyramid deployable truss units

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Chinese Journal of Aeronautics 2019年第7期32卷 1772-1787页

作者： Hui YANG Hongwei GUO Yan WANG Rongqiang LIU Zongquan DENG College of Electrical Engineering and Automation Anhui UniversityHefei230601China State Key Laboratory Robotics and System Harbin Institute of TechnologyHarbin150001China China Electronics Technology Group Corporation No.38Research Hefei230088China

Compared with non-overconstrained deployable units, overconstrained deployable units are widely used in space missions for their higher stiffness characteristics. Besides the performance of a three-step topological structural analysis and design of the rectangular pyramid deployable truss unit(PDTU), conducting a structural synthesis of an overconstrained deployable unit requires the determination of the relative position and direction of each kinematic axis. The structural synthesis of an overconstrained deployable unit is investigated based on screw theory and its topological structure. The possible overconstrained cases of the rectangular PDTUs are analyzed, and corresponding screw expressions are obtained. Thus, the rectangular PDTUs, which can be folded into a plane, are synthesized systemically, and a series of overconstrained rectangular PDTUs is obtained. Furthermore, the feasibility of the folded and deployed motions under one degree of freedom for those deployable units is verified in dynamical simulation by using ADAMS 2010.

关键词： Assembly SAR antenna Common overconstraint Deployable truss structure Screw theory Structural synthesis

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Tunable unidirectional compact acoustic amplifier via space-time modulated membranes

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Physical Review B 2020年第2期102卷 024309-024309页

作者： Xiaohui Zhu Junfei Li Chen Shen Guangyu Zhang Steven A. Cummer Longqiu Li State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin Heilongjiang 150001 China Department of Electrical and Computer Engineering Duke University Durham North Carolina 27708 USA

Space-time modulation has recently attracted considerable attention as it enables new possibilities in wave manipulation and control. Here we propose a tunable unidirectional acoustic amplifier based on a space-time modulated membrane system. The transfer matrix method is applied to design this system and optimize the modulation parameters for the realization of unidirectional amplification. Efficient one-way amplification of acoustic waves is demonstrated theoretically and numerically within a frequency range from 2260 to 2520 Hz, with overall dimension being less than 1/3 of the corresponding wavelength. Across this operation band, the amplification factor in the positive direction varies smoothly from 3.0 to 5.8, while the transmitted wave energy in the negative direction does not change significantly. Our work identifies a feasible approach to realize a tunable unidirectional acoustic amplifier via space-time modulated membranes, which offers a design platform for a number of applications in sensing, imaging, and communication.

关键词： Acoustic metamaterials Acoustic wave phenomena Sound waves

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A Synthetic Framework for Evaluating and Designing an Anthropomorphic Prosthetic Hand

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Journal of Bionic Engineering 2018年第1期15卷 69-82页

作者： Li Jiang Yuan Liu Dapeng Yang Hong Liu State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin 150080 China

The mimic of aesthetics, fianction, and rehabilitation application makes the prosthetic hand design an interdisciplinary, synthetic work. Prosthetic hands should be designed in a comprehensive consideration with a synthetic framework from multiple areas. In this case, a synthetic framework containing 12 anthropomorphism indexes is established and utilized to understand the human hand characteristic and quantifiably evaluate the anthropomorphism of a prosthetic hand. Our quantified evaluation results show that a Global Anthropomorphic Score （GAS） of the current commercial prosthetic hands is only 45.2%. The compliance, coupling speed ratio and configuration of the Degrees Of Freedom （DOF） are found to be the lowest three anthropomorphism evaluation indexes in all 12 indexes. In addition, a design priority is proposed based on the quantified evaluation results and contributes to a prosthetic hand design. Moreover, our correlation analysis results between each index and GAS show that, compared with the conventional evaluation index-grasp gesture, the rotation axis distribution index has a stronger distinguishing capability to the hand performance. Finally, a flowchart of prosthetic hand design was presented for a designer to design a prosthetic hand with a high anthropomorphism.

关键词： prosthetic hand anthropomorphism quantified evaluation bionic design mechanical implementation rehabilitation

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