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The energy-saving advantages of burst-and-glide mode for thunniform swimming

Journal of Hydrodynamics 2018年第6期30卷 1072-1082页

作者： Dan Xia Wei-shan Chen Jun-kao Liu Xiang Luo School of Mechanical Engineering Southeast University State Key Laboratory of Robotics and System Harbin Institute of Technology

This paper explores the energy-saving advantages of the burst-and-glide swimming and compares it with the normal self-swimming for a thunniform swimmer. The virtual swimmer allows us to perform controlled numerical experiments by varying the swinging tail number and the duty cycle while keeping the other parameters fixed. 3-D Navier-Stokes equations are used to compute the viscous flow over the swimmer. The user-defined functions and the dynamic mesh technology are used to simulate the burst-and-glide swimming. The results show that with the increase of the swinging tail number or the duty cycle, the swimming velocity, the power and the efficiency all increase, but the velocity-power ratio decreases somewhat. Therefore, choosing smaller swinging tail number and duty cycle is beneficial in reducing the power and increasing the velocity-power ratio, and thus to obtain the same velocity, less power is consumed. And to swim the same distance, the energy can significantly be saved. The power consumption, the efficiency and the velocity-power ratio in the burst-and-glide case are 43.9%, 40.6% and 1.15 times of those in the normal swimming case, respectively. The flow structures clearly show the evolution process around the fish in the burst-and-glide swimming. The findings can be used to reasonably plan the swimming action and to take the advantage of the external flow field energy for the fishlike robot, to be more efficient and energy-saving.

关键词： Energy-saving advantages burst-and-glide mode normal self-swimming thunniform swimmer

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An Evolutionary Game based Secure Clustering Protocol with Fuzzy Trust Evaluation and Outlier Detection for Wireless Sensor Networks

arXiv

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arXiv 2022年

作者： Yang, Liu Lu, Yinzhi Yang, Simon X. Zhong, Yuanchang Guo, Tan Liang, Zhifang The School of Communication and Information Engineering Chongqing University of Posts and Telecommunications Chongqing China The Advanced Robotics and Intelligent Systems Laboratory School of Engineering University of Guelph GuelphONN1G2W1 Canada The State Key Laboratory of Power Transmission Equipment & System Security and New Technology School of Electrical Engineering Chongqing University Chongqing400044 China

Trustworthy and reliable data delivery is a challenging task in Wireless Sensor Networks (WSNs) due to unique characteristics and constraints. To acquire secured data delivery and address the conflict between security and energy, in this paper we present an evolutionary game based secure clustering protocol with fuzzy trust evaluation and outlier detection for WSNs. Firstly, a fuzzy trust evaluation method is presented to transform the transmission evidences into trust values while effectively alleviating the trust uncertainty. And then, a K-Means based outlier detection scheme is proposed to further analyze plenty of trust values obtained via fuzzy trust evaluation or trust recommendation. It can discover the commonalities and differences among sensor nodes while improving the accuracy of outlier detection. Finally, we present an evolutionary game based secure clustering protocol to achieve a trade-off between security assurance and energy saving for sensor nodes when electing for the cluster heads. A sensor node which failed to be the cluster head can securely choose its own head by isolating the suspicious nodes. Simulation results verify that our secure clustering protocol can effectively defend the network against the attacks from internal selfish or compromised nodes. Correspondingly, the timely data transfer rate can be improved significantly. © 2022, CC BY.

关键词： Sensor nodes

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Design of a close-range radiotherapy particle implantation device

Design of a close-range radiotherapy particle implantation d...

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2019 IEEE International Conference on robotics and Biomimetics, ROBIO 2019

作者： Ban, Guang Li, Changle Zhang, Xuehe Liu, Gangfeng Liu, Yubin Zhao, Jie Zhang, Leifeng Fan, Yilun State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin 150080 NO. 2 YiKuang Street HeiLongJiang Province China

ISBN: (纸本)9781728163215

The validity of brachytherapy has been proved in clinical tumor treatment, and robotic surgery system has been used in recent years to ensure surgical consistency. In our work, a new automatic radioactive particle implantation device with two degrees of freedom was proposed to apply in the brachytherapy robotic surgery system as an end effector. Furthermore, physical assembling and simple function verifying experiments were accomplished. This device can help simplify the operating steps during surgery, and improve the stability of the surgical system, and enhances the surgical efficiency. © 2019 IEEE.

关键词： Robotic surgery

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A new method for fiber bragg grating based needle shape sensing calibration

A new method for fiber bragg grating based needle shape sens...

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2019 IEEE International Conference on robotics and Biomimetics, ROBIO 2019

作者： Zhang, Leifeng Li, Changle Zhang, Xuehe Liu, Gangfeng Liu, Yubin Zhao, Jie Ban, Guang Fan, Yilun Harbin Institute of Technology State Key Laboratory of Robotics and System Harbin 150080 NO. 2 YiKuang Street HeiLongJiang Province China

ISBN: (纸本)9781728163215

Accurate placement of the needle is critical in percutaneous surgery. Needle shape reconstruction technology based on fiber Bragg gratings (FBGs) sensor is considered to have the potential to achieve this goal. In this paper, we present a temperature-insensitive calibration model for calibrating needles with FBG sensors to accurately estimate its deformation. In addition, we have designed a device for simultaneously calibrating the loading direction and shape. Preliminary results indicate that the proposed model is theoretically insensitive to temperature, but in fact it can only be used within a certain temperature range. The resolution of the loading direction increases as the degree of bending increases, with a maximum error of 8.58°. Shape reconstruction error can be less than 1.5mm with small needle bending. This calibration method can meet clinical applications. © 2019 IEEE.

关键词： Fiber Bragg gratings

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Mechanics of soft-body rolling motion without external torque

arXiv

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arXiv 2024年

作者： Liang, Xudong Ding, Yimiao Yuan, Zihao Jiang, Junqi Xie, Zongling Fei, Peng Sun, Yixuan Gu, Guoying Zhong, Zheng Chen, Feifei Si, Guangwei Gong, Zhefeng School of Science Harbin Institute of Technology Shenzhen518055 China Department of Neurology The Fourth Hospital and School of Brain Science and Brain Medicine Zhejiang University School of Medicine Hangzhou310058 China Liangzhu Laboratory MOE Frontier Science Center for Brain Science and Brain-Machine Integration State Key Laboratory of Brain-Machine Intelligence Zhejiang University 1369 West Wenyi Road Hangzhou311121 China NHC and CAMS Key Laboratory of Medical Neurobiology Zhejiang University Hangzhou310058 China State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong University Shanghai200240 China Robotics Institute School of Mechanical Engineering Shanghai Jiao Tong University Shanghai200240 China State Key Laboratory of Brain and Cognitive Science Institute of Biophysics Chinese Academy of Sciences 15 Datun Road Beijing100101 China University of Chinese Academy of Sciences 19A Yuquan Road Beijing100049 China Huazhong University of Science and Technology Optical and Electronic Information Wuhan430074 China Zhejiang Lab. Hangzhou311121 China

The Drosophila larva, a soft-body animal, can bend its body and roll efficiently to escape danger. However, contrary to common belief, this rolling motion is not driven by the imbalance of gravity and ground reaction forces. Through functional imaging and ablation experiments, we demonstrate that the sequential actuation of axial muscles within an appropriate range of angles is critical for generating rolling. We model the interplay between muscle contraction, hydrostatic skeleton deformation, and body-environment interactions, and systematically explain how sequential muscle actuation generates the rolling motion. Additionally, we constructed a pneumatic soft robot to mimic the larval rolling strategy, successfully validating our model. This mechanics model of soft-body rolling motion not only advances the study of related neural circuits, but also holds potential for applications in soft robotics. © 2024, CC BY.

关键词： Pneumatics

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Object-oriented Map Exploration and Construction Based on Auxiliary Task Aided DRL

Object-oriented Map Exploration and Construction Based on Au...

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International Conference on Pattern Recognition

作者： Junzhe Xu Jianhua Zhang Shengyong Chen Honghai Liu College of Computer Science and Technology Zhejiang University of Technology Hangzhou China College of Computer Science and Technology Tianjin University of Technology Tianjin China State Key Laboratory of Robotics and System School of Mechanical Engineering and Automation Harbin Institute of Technology Shenzhen China

Environment exploration by autonomous robots through deep reinforcement learning (DRL) based methods has attracted more and more attention. However, existing methods usually focus on robot navigation to single or multiple fixed goals, while ignoring the perception and construction of external environments. In this paper, we propose a novel environment exploration task based on DRL, which requires a robot fast and completely perceives all objects of interest, and reconstructs their poses in a global environment map, as much as the robot can do. To this end, we design an auxiliary task aided DRL model, which is integrated with the auxiliary object detection and 6-DoF pose estimation components. The outcome of auxiliary tasks can improve the learning speed and robustness of DRL, as well as the accuracy of object pose estimation. Comprehensive experimental results on the indoor simulation platform AI2-THOR have shown the effectiveness and robustness of our method.

关键词： Navigation Object oriented modeling Pose estimation Semantics Object detection Reinforcement learning Robustness

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Power Consumption Characteristics Research on Mobile system of Electrically Driven Large-Load-Ratio Six-Legged Robot

Research Square

引用

Research Square 2021年

作者： Zhuang, Hong-Chao Wang, Ning Gao, Hai-Bo Deng, Zong-Quan School of Mechanical Engineering Tianjin University of Technology and Education Tianjin300222 China School of Information Technology Engineering Tianjin University of Technology and Education Tianjin300222 China State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin150001 China

To research the power consumption characteristics of mobile system of an electrically driven large-load-ratio six-legged robot with engineering capability is beneficial to speed up it toward practicability. Based on the configuration and walking modes of robot, the mathematical model of the power consumption of mobile system is set up. In view of the tripod gait is often selected for the six-legged robots, the simplified power consumption model of mobile system under the tripod gait is established by means of reducing the dimension of the robot's statically indeterminate problem and constructing the equal force distribution. Then, the power consumption of robot mobile system is solved under different working conditions. The variable tendencies of the power consumption of robot mobile system are respectively obtained with changes in the rotational angles of hip joint and knee joint, body height, and span. The articulated rotational zones and the ranges of body height and span are determined under the lowest power consumption. According to the walking experiments of prototype, the variable tendencies of the average power consumption of robot mobile system are respectively acquired with changes in the duty ratio, body height, and span. Then, the feasibility and correctness of theory analysis are verified in the power consumption of robot mobile system. The proposed analysis method in this paper can provide a reference on the lower power research of the large-load-ratio multi-legged robots. © 2021, CC BY.

关键词： Electric power utilization

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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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Time-Optimal Control of Underactuated Wheeled Inverted Pendulum Vehicles Along Specified Paths

Time-Optimal Control of Underactuated Wheeled Inverted Pendu...

引用

International Conference on Advanced robotics and Mechatronics (ICARM)

作者： Yigao Ning Ming Yue Zenan Lin School of Automotive Engineering Dalian University of Technology Dalian China State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin China

ISBN: (数字)9781728164793

ISBN: (纸本)9781728164809

This study proposes a time-optimal control method for a wheeled inverted pendulum (WIP) vehicle under specified paths. Firstly, the given path is described with a parametric form, and the kinematic model, velocity constraint and acceleration constraint are all parameterized with a same parameter as the geometric path. Meanwhile, the stabilization constraint of vehicle body is also formulated through the kinematic coupling relationship to take the underactuated characteristic into full consideration. Next, the time-optimal trajectory is constructed by a sequence of minimum acceleration and maximum acceleration trajectories based on phase-plane analysis, and the optimality is illustrated through rigorous analysis. Finally, a time-optimal trajectory tracking controller is designed for the WIP vehicle to realize the minimum-time motion, and numerical simulation results validate the effectiveness of the proposed method.

关键词： Acceleration Trajectory Mechatronics Kinematics Mobile robots Trajectory tracking

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Review of surgical robotic systems for keyhole and endoscopic procedures:state of the art and perspectives

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Frontiers of Medicine 2020年第4期14卷 382-403页

作者： Yuyang Chen Shu’an Zhang Zhonghao Wu Bo Yang Qingquan Luo Kai Xu State Key Laboratory of Mechanical System and Vibration School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China RII Lab(Lab of Robotics Innovation and Intervention) UM-SJTU Joint InstituteShanghai Jiao Tong UniversityShanghai 200240China Department of Urology Shanghai Changhai Hospitalthe Second Military Medical UniversityShanghai 200433China Shanghai Lung Cancer Center Shanghai Chest HospitalShanghai Jiao Tong UniversityShanghai 200030China

Minimally invasive surgery,including laparoscopic and thoracoscopic procedures,benefits patients in terms of improved postoperative outcomes and short recovery *** challenges in hand–eye coordination and manipulation dexterity during the aforementioned procedures have inspired an enormous wave of developments on surgical robotic systems to assist keyhole and endoscopic procedures in the past *** paper presents a systematic review of the state-of-the-art systems,picturing a detailed landscape of the system configurations,actuation schemes,and control approaches of the existing surgical robotic systems for keyhole and endoscopic *** development challenges and future perspectives are discussed in depth to point out the need for new enabling technologies and inspire future researches.

关键词： surgical robots keyhole surgery endoscopic surgery

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