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Enhanced electrical performance in CaBi_(4)Ti_(4)O_(15)ceramics through synergistic chemical doping and texture engineering

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Journal of Materiomics 2024年第2期10卷 471-479页

作者： Le Zhao Guohao Li Xiao Zhai Weijie Kuai Yuzhi Zhai Gang Tian Zhigang Gai Minglei Zhao Juan Du Hongjun Zhang Limei Zheng School of Information and Automation Engineering Qilu University of Technology(Shandong Academy of Sciences)Jinan250353China School of Physics State Key Laboratory of Crystal MaterialsShandong UniversityJinan250100China Center for Optics Research and Engineering(CORE) Key Laboratory of Laser and Infrared System of Ministry of EducationShandong UniversityQingdaoShandong266237China College of Materials Science and Engineering Liaocheng UniversityLiaocheng252059China Functional Materials and Acoustooptic Instruments Institute School of Instrumentation Science and EngineeringHarbin Institute of TechnologyHarbin150080China

High-temperature piezoelectric materials with excellent piezoelectricity,low dielectric loss and large resistivity are highly desired for many industrial sectors such as aerospace,aircraft and nuclear *** a synergistic design strategy combining microstructural texture and chemical doping is employed to optimize CaBi 4Ti 4O15(CBT)ceramics with bismuth layer *** textured microstructure with an orientation factor of 80%e82%has been successfully achieved by the spark plasma sintering ***,by doping MnO_(2),both advantages of hard doping and sintering aids are used to obtain the excellent electrical performance of d_(33)=27.3 pC/N,tandδ-0.1%,Q_(31)~2,307 and electrical re-sistivityρ~6.5×10^(10)Ω·*** to 600℃,the 0.2%(in mass)Mn doped CBT ceramics still exhibit high performance of d_(33)=26.4 pC/N,r~1.5×10^(6)Ω·cm and tandδ~15.8%,keeping at an applicable level,thus the upper-temperature limit for practical application of the CBT ceramics is greatly *** work paves a new way for developing and fabricating excellent high-temperature piezoelectric materials.

关键词： CaBi_(4)Ti_(4)O_(15) Piezoelectricity Mechanical quality factor Resistivity

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A novel piezoelectric actuated micro-tweezer with force sensing for optical fiber manipulation

A novel piezoelectric actuated micro-tweezer with force sens...

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IEEE International Conference on Real-time Computing and robotics (RCAR)

作者： Haoxiang Zhao Haoran Rong State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin China Heilongjiang University of Science and Technology Harbin China

With the development of micro-electromechanical systems, micro-manipulation robots are extensively used in micro-nano manufacturing due to their high precision. As the core component of the MEMS, the micro-tweezers which are driven by PZT, ultrasonic motors to grasp millimeter and micron objects have developed rapidly. However, it is pretty tough for these tweezers to attain bendy gripping of objects due to the lack of sensors at the cease of the tweezer. Therefore, a force-sensing micro-tweezer with micro-operating device is designed in this paper, which is appropriate for the clamping of optical fibers of different diameters and controlled with the aid of a single-chip microcomputer. The working principle is that the certain opening at the end of the micro-tweezer is closed when the PZT outputs a tiny displacement which is amplified through the two-stage displacement amplifying mechanism, at some stage in which the PWM sign generated by using the controller and amplified by means of the signal amplifier is transmitted in this device and used to control the PZT. To enforce the function of the pressure feedback grasping of optical fibers of distinctive diameters, the sign generated by the pressure sensor at the end of the micro-tweezer is despatched to the controller after the fiber is being clamped. In this paper, the design, simulation and evaluation of the micro-tweezer, the setup and calibration of the system, and the experiments and performance assessments of the micro-tweezer are carried out. The results exhibit that the micro-tweezer can clamp the fiber with diameter of 100-300μm precisely with its output displacement at 360μm, force-sensing resolution accuracy at 9.8mN, and the clamping force at 0.392N. The force-sensing device now not only has a small volume, but also realizes the speedy replacement of a number of components, which advantage it to be widely-used in future micro-tweezers application scenario.

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Viia-hand: a Reach-and-grasp Restoration system Integrating Voice interaction, Computer vision and Auditory feedback for Blind Amputees

arXiv

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arXiv 2023年

作者： Peng, Chunhao Yang, Dapeng Cheng, Ming Dai, Jinghui Zhao, Deyu Jiang, Li State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin150080 China Artificial Intelligence Laboratory Harbin Institute of Technology Harbin150080 China

Visual feedback plays a crucial role in the process of amputation patients completing grasping in the field of prosthesis control. However, for blind and visually impaired (BVI) amputees, the loss of both visual and grasping abilities makes the "easy" reach-and-grasp task a feasible challenge. In this paper, we propose a novel multi-sensory prosthesis system helping BVI amputees with sensing, navigation and grasp operations. It combines modules of voice interaction, environmental perception, grasp guidance, collaborative control, and auditory/tactile feedback. In particular, the voice interaction module receives user instructions and invokes other functional modules according to the instructions. The environmental perception and grasp guidance module obtains environmental information through computer vision, and feedbacks the information to the user through auditory feedback modules (voice prompts and spatial sound sources) and tactile feedback modules (vibration stimulation). The prosthesis collaborative control module obtains the context information of the grasp guidance process and completes the collaborative control of grasp gestures and wrist angles of prosthesis in conjunction with the user's control intention in order to achieve stable grasp of various objects. This paper details a prototyping design (named viia-hand) and presents its preliminary experimental verification on healthy subjects completing specific reach-and-grasp tasks. Our results showed that, with the help of our new design, the subjects were able to achieve a precise reach and reliable grasp of the target objects in a relatively cluttered environment. Additionally, the system is extremely user-friendly, as users can quickly adapt to it with minimal training. Copyright © 2023, The Authors. All rights reserved.

关键词： Computer vision

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A Family of Deployable Single-Loop Metamorphic Mechanisms for Aerospace Manipulators: Synthesis, Network, and Analysis

SSRN

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SSRN 2024年

作者： Zhang, Yang Kang, Xi Li, Bing State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin150001 China Guangdong Provincial Key Laboratory of Intelligent Morphing Mechanisms and Adaptive Robotics Harbin Institute of Technology Shenzhen518052 China School of Mechanical Engineering and Automation Harbin Institute of Technology Shenzhen518052 China

Guided by predetermined degrees of freedom for different desired tasks, the type synthesis of single-loop metamorphic mechanisms (SLMMs) has long posed a challenge. Owing to the complexity and coupling of their overconstraints and the variability of constraints arising from bifurcation motions, it is difficult to ensure geometric coordination and synchronous motion for a network of multiple SLMMs. Here, we propose an approach to type synthesize SLMMs using the atlas method. A novel family of SLMMs is further synthesized. The mobility analysis of a selected 7R SLMM is carried out via screw theory. The kinematics and bifurcation phenomena are analyzed and verified through numerical simulation using computer-aided design models. To evaluate the performance of the SLMMs, the mapping relationship between key design parameters and performance indicators, such as the grasping angle, folding angle, and mechanical advantage, is studied. A networking method is then proposed by considering the geometric coordination conditions and variation of the overconstraints of SLMMs. Prototypes of an SLMM and manipulator with optimal geometrical parameters are developed to verify the feasibility and correctness of the proposed method and kinematic analysis. © 2024, The Authors. All rights reserved.

关键词： Manipulators

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Open-Source Reinforcement Learning Environments Implemented in MuJoCo with Franka Manipulator

Open-Source Reinforcement Learning Environments Implemented ...

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IEEE/ASME (AIM) International Conference on Advanced Intelligent Mechatronics

作者： Zichun Xu Yuntao Li Xiaohang Yang Zhiyuan Zhao Lei Zhuang Jingdong Zhao State Key Laboratory of Robotics and Systems Harbin Institute of Technology Harbin Heilongjiang Province China

ISBN: (数字)9798350355369

ISBN: (纸本)9798350355376

This paper presents three open-source reinforcement learning environments developed on the MuJoCo physics engine with the Franka Emika Panda arm in MuJoCo Menagerie. Three representative tasks, push, slide, and pick-and-place, are implemented through the Gymnasium robotics API, which inherits from the core of Gymnasium. Both the sparse binary and dense rewards are supported, and the observation space contains the keys of desired and achieved goals to follow the Multi-Goal Reinforcement Learning framework. Three different off-policy algorithms are used to validate the simulation attributes to ensure the fidelity of all tasks, and benchmark results are also given. Each environment and task are defined in a clean way, and the main parameters for modifying the environment are preserved to reflect the main difference. The repository, including all environments, is available at https://***/zichunxx/panda_mujoco_gym.

关键词： Mechatronics Reinforcement learning Benchmark testing Manipulators Task analysis Physics Engines

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Comprehensive Performance Optimization of a Novel Anthropomorphic Dexterous Hand

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IEEE robotics and Automation Letters 2025年第7期10卷 6816-6823页

作者： Ma, Yifan Shang, Weiwei Zhang, Fei Pang, Shunxiang Dai, Shuqing Yi, Zhengkun Li, Guotao Cong, Shuang University of Science and Technology of China Department of Automation Jinzhai Road 96 Hefei230027 China Shenzhen Institute of Advanced Technology Chinese Academy of Sciences Guangdong Provincial Key Laboratory of Robotics and Intelligent System Shenzhen518055 China Institute of Automation Chinese Academy of Sciences State Key Laboratory of Multimodal Artificial Intelligence Systems Beijing100190 China

Grasp and in-hand manipulation of dexterous hands are essential for daily operational tasks. In this study, an optimized design method for a novel anthropomorphic dexterous hand is proposed, which improves the comprehensive performance of grasp and manipulability of the dexterous hand. The constraints of multi-fingered contact force and kinematics are established with full consideration of the applicability to the objects of different sizes and the shape characteristics of finger contact surface. The performance index of in-hand manipulation ability is proposed, and the optimization problem is constructed through the technique for order preference by similarity to ideal solution (TOPSIS) to achieve multi-objective optimization of precision grasp and in-hand manipulation. Finally, simulation and experiment verify the feasibility of our prototype and optimization method. The results show that the in-hand translation space and in-hand rotation range are increased by 20% and 8.5%, respectively. Our dexterous hand has excellent abilities of multi-fingered interaction and in-hand manipulation, which can perform 33 grasp gestures and two/three-fingered in-hand manipulation. This study provides a valuable reference for the design of dexterous hands with anthropomorphic functions. © 2016 IEEE.

关键词： Multiobjective optimization

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MECHANICAL CHARACTERISTICS ANALYSIS OF CORNER TENSIONED RECTANGULAR THIN MEMBRANES 1

MECHANICAL CHARACTERISTICS ANALYSIS OF CORNER TENSIONED RECT...

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1st International Conference on Mechanical system Dynamics, ICMSD 2022

作者： Li, Bingyan Peng, Tao Lin, Qiuhong Wang, Xiaoyu Cong, Qiang Tian, Xinqi Liu, Rongqiang Beijing Institute of Spacecraft Engineering Beijing100094 China State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin150001 China College of Mechanical and Electrical Engineering Harbin Engineering University Harbin150001 China

ISBN: (数字)9781839537837

ISBN: (纸本)9781839537837

This paper presents the calculation of the stress distribution of corner tensioned rectangular thin membrane based on the stress superposition method (SSM). By comparing with the results of finite element simulation, the theoretical results of stress distribution of tensioned membrane structure are verified. Based on SSM and free vibration calculation theory, the effects of tension boundary parameters on membrane stress distribution and models are investigated. The influence of corner tension on the mechanical characteristics is analyzed for the corner tensioned rectangular membranes with different aspect ratios. The formula for each order's fundamental frequency ratio of atmospheric to spatial environment is proposed. Conducting the dynamics experiment of a rectangular tensioned membrane, the theoretical analysis is verified by the experimental modal results. © 2022 IET Conference Proceedings. All rights reserved.

关键词： Stress concentration

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Transfer force perception skills to robot‐assisted laminectomy via imitation learning from human demonstrations

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CAAI Transactions on Intelligence technology 2024年第4期9卷 903-916页

作者： Meng Li Xiaozhi Qi Xiaoguang Han Ying Hu Bing Li Yu Zhao Jianwei Zhang Harbin Institute of Technology ShenzhenChina Shenzhen Institute of Advanced Technology Chinese Academy of SciencesShenzhenChina Shenzhen Key Laboratory of Minimally Invasive Surgical Robotics and System Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenChina Beijing Jishuitan Hospital Capital Medical UniversityBeijingChina Department of Orthopedics Peking Union Medical College HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina University of Hamburg Hamburg22527Germany

A comparative study of two force perception skill learning approaches for robot‐assisted spinal surgery,the impedance model method and the imitation learning(IL)method,is *** impedance model method develops separate models for the surgeon and patient,incorporating spring‐damper and bone‐grinding *** surgeons'feature parameters are collected and mapped using support vector regression and image navi-gation *** imitation learning approach utilises long short‐term memory networks(LSTM)and addresses accurate data labelling challenges with custom *** results demonstrate skill recognition rates of 63.61%-74.62%for the impedance model approach,relying on manual feature ***,the imitation learning approach achieves a force perception recognition rate of 91.06%,outperforming the impedance model on curved bone *** findings demonstrate the potential of imitation learning to enhance skill acquisition in robot‐assisted spinal surgery by eliminating the laborious process of manual feature extraction.

关键词： learning(artificial intelligence) medical applications medical signal processing robotics

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Mag-Boost Mechanism for High-Power Ocean Wave Energy Harvesting

SSRN

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SSRN 2024年

作者： Tang, Tianyi Li, Yunfei Huang, Manjuan Mei, Mingqi Wang, Zizhao Zha, Fusheng Sun, Lining Liu, Huicong School of Mechanical and Electrical Engineering Jiangsu Provincial Key Laboratory of Advanced Robotics Soochow University Suzhou215123 China State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin150001 China

Ocean wave energy is a highly anticipated renewable energy source. However, due to the ultra-low frequency and random characteristics of ocean waves, efficient and high-power energy harvesting has been a great challenge. By ingeniously leveraging the phenomenon of sudden magnetic-torque variation in orthogonal magnetic fields, this paper proposes an innovative Mag-Boost mechanism, which is capable of converting ultra-low excitation below 1Hz to high-frequency oscillations of power-magnet more than 50Hz without direct contact. The energy conversion efficiency of this mechanism can be as high as 89.3%. By integrating four Mag-boost units into a circular array, a high-power wave energy harvester (WEH) with ultra-low frequency response capabilities has been proposed. At a frequency of 1Hz and an inclination angle of 30°, the WEH demonstrated a high output performance with power of 1.79W and power density of 1.88kW/m³, which is an order of magnitude higher than those of the previous reported ones. During the off-shore test at Yellow Sea, the WEH reached the peak open-circuit voltage of 10V, ensuring completely independent and stable power supply for wireless temperature and humidity sensors. Furthermore, the Mag-Boost mechanism also shows considerable potential for harvesting other forms of low-frequency environmental energy, including wind, vibration, and human kinetic energy. © 2024, The Authors. All rights reserved.

关键词： Water waves

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AEROENGINE remaining life prediction based on grey similarity multiscale matching 20

AEROENGINE remaining life prediction based on grey similarit...

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20th International Conference on Condition Monitoring and Asset Management, CM 2024

作者： Sun, Shilong Huang, Haodong Ding, Jian Lu, Wenjie Wang, Dong School of Mechanical Engineering and Automation Harbin Institute of Technology Guangdong Shenzhen518055 China Guangdong Provincial Key Laboratory of Intelligent Morphing Mechanisms and Adaptive Robotics Shanghai Jiao Tong University Shanghai200240 China State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong University Shanghai200240 China

ISBN: (纸本)9780903132848

In this paper, we address the challenge of predicting the remaining useful life (RUL) of aero-engines, which are critical components of aircraft that operate under increasingly extreme conditions as engine performance enhances. Ensuring the safety and reliability of these engines is paramount. To this end, we introduce a novel RUL prediction methodology that leverages grey similarity multiscale matching. This approach employs the robust capabilities of Long Short-Term Memory (LSTM) networks for processing time-series data. Specifically, an LSTM Stacked AutoEncoder (L-SAE) is designed to extract pivotal operational features of the engine, thereby delineating its degradation trajectory. Furthermore, the grey correlation analysis is utilized to assess the similarity between these degradation trajectories, which is complemented by a multi-time scale sliding window technique for enhanced similarity matching. Subsequently, kernel density estimation is applied to gauge the uncertainty associated with the prediction outcomes. The efficacy and superiority of our proposed method are demonstrated through the validation of the experiment study. Comparative analysis reveals that our method outperforms existing techniques in key evaluation metrics, underscoring its potential applicability to large-scale datasets. This validation not only confirms the method’s effectiveness but also its advantage in predicting the RUL of aero-engines with greater accuracy and reliability. © 2024 20th International Conference on Condition Monitoring and Asset Management, CM 2024. All rights reserved.

关键词： Long short-term memory

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