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Reliability Evaluation of Wind Power Converter Under Fault-tolerant Control Scheme with Quantification of Temperature and Humidity Effects

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Journal of Modern Power systems and Clean Energy 2023年第5期11卷 1700-1710页

作者： Xueying Yu Bo Hu Kaigui Xie Changzheng Shao Yunjie Bai Wenyuan Li Jinfeng Ding State Key Laboratory of Power Transmission Equipment and System Security Chongqing UniversityChongqing 400030China

Wind power converter(WPC)is a key part of a wind power unit which delivers electric energy to power *** of a large number of semiconductors,WPC has a high failure *** paper proposes a method to accurately evaluate the reliability of WPC,which is crucial for the design and maintenance of wind ***,the index of effective temperature(ET)is presented to quantify the effects of temperature and humidity on the semiconductor operation.A novel method is proposed to evaluate the lifetime and calculate the aging failure rates of the semiconductors considering the fluctuations of ***,the failure mode and effect analysis(FMEA)of WPC is investigated based on the topology and control *** conventional two-state reliability model of the WPC is extended to the multi-state reliability model where the partial working state under the fault-tolerant control scheme is ***,a reliability evaluation framework is established to calculate the parameters of the WPC reliability model considering the variable failure rates and repair activities of *** studies are designed to verfify the proposed method using a practical wind turbine.

关键词： Effective temperature(ET) fault-tolerant control scheme humidity reliability evaluation wind power converter(WPC)

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RGB-D Camera Based Map Building and Path Planning of Snake Robot 16th

RGB-D Camera Based Map Building and Path Planning of Snake R...

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

作者： Sun, Yongjun Wang, Qiang Xue, Zhao Liu, Rongqiang Liu, Hong State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin150001 China

ISBN: (纸本)9789819964826

Snake robot is a robot that can move freely in a small and complex space with super-redundant DOF and motion flexibility, and it has been proven to have a wide range of application prospects. RGB-D camera is a new type of visual sensor that can directly obtain color images and depth information. To enable the snake robot to work in some special task environments, we developed an orthogonal modular snake robot using RGB-D cameras, and conducted research on snake robot map building and path planning. An improved Batch Informed Tree (BIT*) algorithm is proposed. Finally, to verify the effectiveness of the proposed method, a corresponding experimental program is designed and related experimental analysis is carried out. The results show that our designed snake robot can complete the task of map building and path planning. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Motion planning

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Control of myoelectric prosthetic hand with a novel proximity-tactile sensor

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Science china(Technological Sciences) 2022年第7期65卷 1513-1523页

作者： YANG Bin JIANG Li GE ChuanYang CHENG Ming ZHANG Jia State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150080China Key Laboratory of Microsystems and Microstructure Manufacturing Ministry of Education Harbin Institute of TechnologyHarbin 150080China

Currently, prosthetic hands can only achieve several prespecified and discrete hand motion patterns from popular myoelectric control schemes using electromyography(EMG) signals. To achieve continuous and stable grasping within the discrete motion pattern, this paper proposes a control strategy using a customized, flexible capacitance-based proximity-tactile sensor. This sensor is integrated at the fingertip and measures the distance and force before and after contact with an object. During the pregrasping phase, each fingertip’s position is controlled based on the distance between the fingertip and the object to make all fingertips synchronously approach the object at the same distance. Once contact is established, the sensor turns to output the tactile information, by which the contact force of each fingertip is finely controlled. Finally, the method is introduced into the human-machine interaction control for a myoelectric prosthetic hand. The experimental results demonstrate that continuous and stable grasping could be achieved by the proposed control method within the subject’s discrete EMG motion mode. The subject also obtained tactile feedback through the transcutaneous electrical nerve stimulation after contact.

关键词： prosthetic hand proximity tactile sensor myoelectric control sensory feedback

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PCE: Multi-Agent Path Finding via Priority-Aware Communication & Experience Learning

IEEE Transactions on Intelligent Vehicles

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IEEE Transactions on Intelligent Vehicles 2024年 1-13页

作者： Gao, Jianqi Li, Yanjie Ye, Zhaohui Wu, Xinyu Department of Guangdong Key Laboratory of Intelligent Morphing Mechanisms and Adaptive Robotics and School of Mechanical Engineering and Automation Harbin Institute of Technology Shenzhen China Guangdong Provincial Key Laboratory of Robotics and Intelligent System Shenzhen Institute of Advanced Technology Chinese Academy of Sciences Shenzhen China

Multi-agent path finding (MAPF) is an essential issue for warehouse automation, where multiple agents plan collision-free paths from the start to goal positions. Reinforcement learning (RL) has been employed to develop partially observable distributed MAPF methods that can be scaled to any number of agents. However, existing RL-based MAPF methods still have some limitations in handling redundant information and avoiding deadlock, resulting in a low success rate or longer makespan. This paper proposes a Priority-aware Communication & Experience learning method (PCE), which combines RL with a novel priority-aware multi-agent communication and a new priority-aware deadlock experience replay to tackle this challenge. To be specific, our innovation encompasses two-fold. Our proposed communication mechanism aims to handle redundant information, which establishes a dynamic communication topology based on agents' priorities and proposes a two-head priority-aware graph attention network to aggregate information. In order to help the agent avoid deadlock, we prioritize the expert experience that solves the deadlock when performing experience replay. We conduct multiple simulation experiments on warehouse-like structured grid maps. Compared with the state-of-the-art RL-based MAPF methods, PCE performs significantly better with a higher success rate and lower makespan in small and large MAPF and higher average throughput in the lifelong MAPF, which can further improve the efficiency of warehouse automation. Finally, we validate PCE using three Turtlebot3-Burger robots, which shows that PCE can be applied in real warehouse automation scenarios. IEEE

关键词： Aggregates

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Method for Evaluating Bolt Competitive Failure Life Under Composite Excitation

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Chinese Journal of Mechanical Engineering 2023年第4期36卷 372-384页

作者： Guangwu Yang Long Yang Han Zhao Haoxu Ding Bing Yang Shoune Xiao State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu 610031China

In this study,the competitive failure mechanism of bolt loosening and fatigue is elucidated via competitive failure tests on bolts under composite *** on the competitive failure mechanism,the mode prediction model and“load ratio-life prediction curve”(ξ-N curve)of the bolt competitive failure are *** the poor correlation of theξ-N curve,an evaluation model of the bolt competitive failure life is proposed based on Miner’s linear damage accumulation *** on the force analysis of the thread surface and simulation of the bolt connection under composite excitation,a theoretical equation of the bolt competitive failure life is established to validate the model for evaluating the bolt competitive failure *** results reveal that the proposed model can accurately predict the competitive failure life of bolts under composite excitation,and thereby,it can provide guidance to engineering applications.

关键词： Bolt Competitive failure life Evaluation model Mode prediction model Composite excitation

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Design and Implementation of Quasi-Direct-Drive Legs for a Frog-Like Jumping Robot 3

Design and Implementation of Quasi-Direct-Drive Legs for a F...

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3rd International Conference on Computer, Control and robotics, ICCCR 2023

作者： Zhihui, Dong Jizhuang, Fan Qilong, Du Jie, Zhao Harbin Institute of Technology State Key Laboratory of Robotics and System Harbin150001 China

ISBN: (纸本)9781665492126

This study aims to design and optimize a motor-driven frog-like jumping robot leg for efficient vertical jumps and multiple consecutive horizontal jumps. We have conducted bionic research on frog legs' structure and motion characteristics and further explored their motion mechanism, providing new ideas and methods for designing and manufacturing robots with high mobility and adaptability. First, our research team designed a robot leg prototype based on the frog's body structure, optimized the robot using computer-Aided design software, and selected a suitable motor-driven actuator. Secondly, the weight reduction optimization of the robot body is carried out regarding material selection and topology optimization to improve the robot's maneuverability and jump height. Finally, after manufacturing the prototype of the robot legs, the robot is experimentally verified. The results show that the robot legs can achieve efficient vertical jumps (the maximum height is 1.40 meters, about 7.8 times the length of the leg link). It can also jump multiple times consecutively, which is significant for applying robots in dangerous environments, search and rescue, and other fields. © 2023 IEEE.

关键词： Machine design

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Aerodynamic Analysis and Deployment Mechanism of A Foldable Mars Quadrotor 20

Aerodynamic Analysis and Deployment Mechanism of A Foldable ...

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20th IEEE International Conference on Mechatronics and Automation, ICMA 2023

作者： Zhu, Kaijie Tang, Dewei Quan, Qiquan Wang, Kaiyi Dong, Yachao Deng, Zongquan Harbin Institute of Technology State Key Laboratory of Robotics and System Harbin150001 China

ISBN: (纸本)9798350320831

The Mars quadrotor is a vertical take-off and landing aerial platform developed to enhance the efficiency of Mars exploration. The four-blade rotor has a high thrust coefficient due to its high solidity, which enables the quadrotor to navigate the Martian atmospheric environment efficiently. This paper proposes a payload-carrying Mars quadrotor featuring four four-bladed rotors that can fold along the rotor arms. The computational fluid dynamics (CFD) method is employed to perform numerical hovering simulations, exploring the propulsion capability and aerodynamic efficiency of rotors with different diameters. The mass distribution and hovering time are estimated when the quadrotor consists of the rotors with the highest figure of merit. The results demonstrate that a larger rotor diameter of the quadrotor yields greater payload capacity and shorter hovering time. During the launch, the quadrotor is folded and constrained within an envelope to protect it from vibrations and shocks. A lifting mechanism with shape-constraint slides is utilized for quadrotor deployment. © 2023 IEEE.

关键词： Efficiency

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Torque Ripple Suppression Under Open-Circuit Fault for DTPPMSM Considering Back EMF Harmonics

Torque Ripple Suppression Under Open-Circuit Fault for DTPPM...

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2023 IEEE International Conference on Applied Superconductivity and Electromagnetic Devices, ASEMD 2023

作者： Liu, Chengsi Zou, Jibin Harbin Institute of Technology Hit State Key Laboratory of Robotics and System Harbin China

ISBN: (纸本)9798350301571

This paper analyzed the impact of phase back electromotive force (back EMF) harmonics on torque of dual three phase permanent magnet synchronous motor (DTPPMSM) from the view of electromagnetic power, and proposed a torque ripple suppression fault-tolerant method for open-circuit fault of DTPPMSM. The proposed method can consider the phase back EMF harmonics, thus achieveing both minimum torque ripple and maximum average torque. The proposed method is verified by both finite element analysis (FEA) and prototype experiment. © 2023 IEEE.

关键词： Dual three phase permanent magnet synchronous motor (DTPPMSM) fault-tolerant finite element analysis (FEA) open circuit

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Learning Agile Quadrotor Flight in Restricted Environments with Safety Guarantees

IEEE Transactions on Intelligent Vehicles

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IEEE Transactions on Intelligent Vehicles 2024年第9期9卷 1-8页

作者： Chen, Shiyu Li, Yanjie Lou, Yunjiang Lin, Ke Wu, Xinyu Department of Control Science and Engineering Harbin Institute of Technology Shenzhen and Guangdong Key Laboratory of Intelligent Morphing Mechanisms and Adaptive Robotics Shenzhen China Guangdong Provincial Key Laboratory of Robotics and Intelligent System Shenzhen Institute of Advanced Technology Chinese Academy of Sciences Shenzhen China

With the increasing requirement for agile and efficient controllers in safety-critical scenarios, controllers that exhibit both agility and safety are attracting attention, especially in the aerial robotics domain. This paper focuses on the safety issue of Reinforcement Learning (RL)-based control for agile quadrotor flight in restricted environments. To this end, we propose a unified Adaptive Safety Predictive Corrector (ASPC) to certify each output action of the RL-based controller in real-time, ensuring its safety while maintaining agility. Specifically, we develop the ASPC as a finite-horizon optimal control problem, formulated by a variant of Model Predictive Control (MPC). Given the safety constraints determined by the restricted environment, the objective of minimizing loss of agility can be optimized by reducing the difference between the actions of RL and ASPC. As the safety constraints are decoupled from the RL-based control policy, the ASPC is plug-and-play and can be incorporated into any potentially unsafe controllers. Furthermore, an online adaptive regulator is presented to adjust the safety bounds of the state constraints with respect to the environment changes, extending the proposed ASPC to different restricted environments. Finally, simulations and real-world experiments are demonstrated in various restricted environments to validate the effectiveness of the proposed ASPC. IEEE

关键词： Reinforcement learning

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Comparison-embedded evidence-CNN model for fuzzy assessment of wear severity using multi-dimensional surface images

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Friction 2024年第6期12卷 1098-1118页

作者： Tao SHAO Shuo WANG Qinghua WANG Tonghai WU Zhifu HUANG Key Laboratory of Education Ministry for Modern Design and Rotor-Bearing System Xi’an Jiaotong UniversityXi’an 710049China State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong UniversityXi’an 710049China

Wear topography is a significant indicator of tribological behavior for the inspection of machine health *** intelligent in-suit wear assessment method for random topography is here ***-dimension(3D)topography is employed to address the uncertainties in wear ***,3D topography reconstruction from a worn surface is accomplished with photometric stereo vision(PSV).Then,the wear features are identified by a contrastive learning-based extraction network(WSFE-Net)including the relative and temporal prior knowledge of wear ***,the typical wear degrees including mild,moderate,and severe are evaluated by a wear severity assessment network(WSA-Net)for the probability and its associated uncertainty based on subjective *** integrating the evidence information from 2D and 3D-damage surfaces with Dempster–Shafer(D–S)evidence,the uncertainty of severity assessment results is further *** proposed model could constrain the uncertainty below 0.066 in the wear degree evaluation of a continuous wear experiment,which reflects the high credibility of the evaluation result.

关键词： wear severity assessment contrastive learning subjective logic Dempster-Shafer(D-S)evidence theory

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