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SSRN 2024年

作者： Cheng, Linhai Gu, Haifeng Chen, Bin Shi, Yiyan Tang, Wei College of Nuclear Science and Technology Harbin Engineering University Harbin150001 China Heilongjiang Provincial Key Laboratory of Nuclear Power System and Equipment Harbin Engineering University Harbin150001 China China Nuclear Power Technology Research Institute Guangdong Key Laboratory of Nuclear Power Safety Guangdong Prov Shenzhen518026 China

This work describes an experimental investigation into the flow and heat transfer properties of single-phase water in a diabatic helically coiled pipe. The pipe has an inner diameter of 8.8 mm and a coiled diameter of 568 mm. Combined with the curve of friction coefficient(f) and heat transfer coefficient(htc) with Reynolds, it can be seen that the transition process from the laminar flow region to the turbulent flow region is relatively slow. When Reynolds is 1.5×105, the friction coefficient has completed the transition stage from laminar flow to turbulent flow. However, the htc only begins to transition at a Reynolds number of 1.5×105 and does not begin to transition into the turbulent region until 2×*** ESDU empirical equation can predict the f of the laminar, transition, and turbulent flow region. The average deviation between the ESDU’s formula and the test data is 0.06% after correcting the wall temperature and pipe roughness. The expression of Cioncolini's empirical formula can reflect the transformation characteristics of the htc from laminar flow to turbulence. This paper revised Cioncolini's empirical formula, and the deviation between the formula and test data in the laminar flow region is -3,86%, and the average deviation in the turbulence region is 0.508%. © 2024, The Authors. All rights reserved.

关键词： Laminar flow

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Analysis of Flow Heat Transfer Characteristics of Helium-Xenon Gas Mixtures During Natural Circulation

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SSRN 2024年

作者： Wang, Xianbo Xie, Lin Bao, Hui Zhao, Fulong Tian, Youyou Liao, Haoyang Tian, Ruifeng Tan, Sichao Heilongjiang Provincial Key Laboratory of Nuclear Power System & Equipment Harbin Engineering University Harbin150001 China Key Laboratory of Nuclear Safety and Advanced Nuclear Energy Technology Ministry of Industry and Information Technology Harbin Engineering University Harbin150001 China Nuclear Power Institute of China Sichuan Province Chengdu610000 China

Helium-xenon gas mixture is a commonly used cooling medium in fourth-generation advanced reactor systems. The thermal conductivity of a passive waste heat system is related to the safety and reliability of the reactor system. Therefore, it is crucial to explore the passive characteristics of the helium-xenon gas mixture. The passive waste heat removal characteristics of a helium-xenon gas mixture are influenced by the flow and heat transfer characteristics of the mixture. However, existing research on the flow and heat transfer characteristics of helium-xenon gas mixture mainly focuses on single tube bundles and plate bundles with fixed flow rates and high Reynolds numbers. However, the natural circulation flow velocity under the influence of gravity changes with heating power, and the Reynolds numbers are all less than 15,000. Lack of research on convective heat transfer characteristics of the helium-xenon gas mixture at low Re. Therefore, this article conducts a study on the flow and heat transfer characteristics of helium xenon under natural circulation conditions. A 1:1 three-dimensional model of the experimental system was constructed using the CFD numerical calculation method. By comparing the experimental values with the calculation results, it was found that the error was less than 10%. This proves that the modified SST k-ω turbulence model can be used to study the flow and heat transfer characteristics of the helium-xenon gas mixture in subsequent natural circulation states. On this basis, natural cycle numerical simulations of helium xenon mixtures with different mixing ratios were carried out at a heat flux of 5000 W/m2, as well as natural cycle numerical simulations of 40 g/mol helium-xenon gas mixture at different heating powers, in order to study the effects of heating power and helium xenon mixing ratio on the natural cycle heat transfer characteristics of the helium-xenon gas mixture. The existing helium-xenon gas mixture flow heat transfer equation

关键词： Helium

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The Application of Acceleration-Level Quaternion Interpolation in the Visual-Servoing Process

The Application of Acceleration-Level Quaternion Interpolati...

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International Conference on Computer and Automation Engineering, ICCAE

作者： Xiaoyu Zhao Yang Liu Zongwu Xie State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin China

Visual servoing process is widely applied in robot control. In the visual servoing process, an interpolation of the robot end pose is necessary. In the interpolation, quaternion suffers a lot for the discontinuity in trajectory velocity and acceleration. In this paper, we propose an acceleration-level continuous interpolation method and apply it to visual servoing process. In the method, we make up use of the conversion between different rotation descriptors and achieve a smooth enough trajectory. Simulations and experiments are carried out to validate the method and the results show considerable performance.

关键词： Interpolation Visualization Automation Quaternions Computational modeling Robot control Process control

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Multi-Slip Conditions Acquisition of Planetary Rovers with Application to Terrain Parameter Identification*

Multi-Slip Conditions Acquisition of Planetary Rovers with A...

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International Conference on Mechatronics and Machine Vision in Practice (M2VIP)

作者： Ye Yuan Huaiguang Yang Chaojie Yang Liang Ding Haibo Gao Nan Li State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin China

ISBN: (纸本)9781665431545

Planetary rovers, integrated with the state-of-the-art technologies in different fields, are required to explore extraterrestrial surfaces to achieve their scientific goals. The perception of the extraterrestrial environment, especially the terrain, greatly affects the mobility of rovers. The estimation of terrain parameters often requires wheel-terrain interaction data under various slip ratios. The data of multi-slip conditions can be obtained by adjusting the slope angles of the terrain or rover load in experiments. However, these methods are neither safe nor practical for planetary rovers that are exploring extraterrestrial planets. In this study, the required wheel slip conditions can be obtained based on the Monte Carlo method and terramechanics theory, by actively adjusting rotation speeds of the rover’s wheels. Simulations in the Vortex physics engine environment verified that the proposed method could generate the multi-slip conditions in a flat terrain without requiring the rover to go up/down high slopes. Furthermore, by measuring the wheel-terrain interaction data, normal force, drawbar pull, driving torque, sinkage under various slip ratios the terrain parameters can be estimated.

关键词： Space vehicles Torque Parameter estimation Monte Carlo methods Mechatronics Planets Machine vision

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Ultra-Low Limit-of-Detection Label-Free Biosensing Utilizing Mode Splitting in Subwavelength Grating Metamaterial Microring Resonators

Ultra-Low Limit-of-Detection Label-Free Biosensing Utilizing...

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Pacific Rim Conference on Lasers and Electro-Optics (CLEO/Pacific Rim)

作者： Wanxin Li Jiewen Li Rui Li Ke Li Yong Yao Jianan Duan Xiaochuan Xu State Key Laboratory on Tunable Laser Technology Guangdong Provincial Key Laboratory of Integrated Photonic-Electronic Chip Guangdong Provincial Key Laboratory of Aerospace Communication and Networking Technology Harbin Institute of Technology Xili University Town Harbin Institute of Technology campus Shenzhen Guangdong China

In this paper, we demonstrate an on-chip biosensor for streptavidin detection with a limit-of-detection as low as 0.01 pg/mL ( $\sim$ 0.167 fM) by leveraging the mode splitting in subwavelength grating metamaterial mi... 详细信息

ISBN: (数字)9798350372076

ISBN: (纸本)9798350372083

关键词： Frequency modulation Lasers and electrooptics Laser modes Metamaterials system-on-chip Gratings Biosensors

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A Model-Free Synchronous Control of Humanoid Robot Finger

A Model-Free Synchronous Control of Humanoid Robot Finger

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IEEE International Conference on robotics and Automation (ICRA)

作者： Ziqi Liu Li Jiang Bin Yang Chongyang Li Ming Cheng Shaowei Fan Dapeng Yang State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin China

For a multi-fingered robot hand, the individual control over single joints cannot guarantee their fine collaboration. For achieving a high-precision synchronization, a theory of synchronous control is introduced to multi-fingered robot hands. This paper introduced a new model-free and cross-coupling control strategy. It had been tested on the humanoid robot fingers and showed high positioning performance. For realizing the mutual influence between the control of all joints, we establish the synchronization error by the differential disposal of adjacent actuator errors, then position errors and synchronization errors are incorporated into a unified control frame. Meanwhile, considering the complex dynamic formulations of the dexterous hand and the characteristics of the control system, a model-free, cross-coupled trajectory tracking method is introduced and the explicit dynamic modeling parameters is not necessary. Finally, we tested our method on a multi-fingered hand platform HIT/DLR-II. The results prove that the new method has superior performance over traditional non-synchronous approaches.

关键词： Automation Trajectory tracking Conferences Force Humanoid robots Collaboration Kinematics

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Design and Analysis of a Variable-sweep Morphing Wing for UAV Based on a Parallelogram Mechanism

Design and Analysis of a Variable-sweep Morphing Wing for UA...

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IEEE International Conference on robotics and Biomimetics

作者： Guang Yang Hongwei Guo Hong Xiao Yue Bai Rongqiang Liu State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin China

ISBN: (纸本)9781665405362

The variable-sweep wing for unmanned aerial vehicle (UAV) can greatly improve the aerodynamic performance at high-speed and low-speed by changing the sweep angle. In this paper, a shear variable-sweep wing is proposed and studied based on a parallelogram mechanism. The skeleton of morphing wing is a single-degree-of-freedom mechanism composed of parallelogram mechanism unit topology. The skin of morphing wing is applied an innovative Kevlar/carbon fiber hybrid composite skin. The composite skins are stitched to the skeleton and sheared as the sweep-angle changes. The kinematics model of the morphing wing is established, and the wing area, aspect ratio, root-to-tip ratio and relative thickness are analyzed. Moreover, establish the composite skin buckling model and obtain the skin parameters that can be smoothly and continuously deformed within the range of sweep-angle changes. Finally, the variable-sweep morphing wing prototype is developed and scanned to verify the smoothness of the designed morphing skins and the deformation performance of morphing wing.

关键词： Deformable models Prototypes Kinematics Autonomous aerial vehicles Aerodynamics Skin Skeleton

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Design and Control of a Hydraulic Driven Robotic Gripper

Design and Control of a Hydraulic Driven Robotic Gripper

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IEEE International Conference on robotics and Biomimetics

作者： Jiahui Qi Xu Li Zhenguo Tao Haibo Feng Yili Fu State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin China

ISBN: (纸本)9781665405362

The robots with robotic grippers can take the place of human to carry objects and use tools efficiently in different situations. This paper presents a novel hydraulic driven robotic gripper named the WLRG-I (the first generation of Wheel-legged robot gripper) which bears large load and has strong robustness. The WLRG-I is installed on the wheel-legged humanoid robot arm to make the WLR-III (the third generation of Wheel-legged robot) have the capability of grasping daily tools and fulfilling special operation tasks in harsh environments. This paper focuses on the design of gripper transmission structure, kinematics and statics. Firstly, the linkage mechanism is proposed according to the design goal. Then, the kinematics and statics of the gripper are studied, and a structural model is established. In addition, PID controller is used to control the position of the gripper with angle feedback. Finally, position tracking and load experiments are completed to verified the accuracy of the control. The gripper can grasp objects of 20kg with 2.15kg dead weight. To the authors’ best knowledge, robot grippers with such a high load-to-weight ratio are very rare.

关键词： Humanoid robots Kinematics Hydraulic systems Manipulators Robustness Mobile robots Grippers

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A Bistable Jumping Robot with Pure Soft Body Actuated by Twisted Artificial Muscle

A Bistable Jumping Robot with Pure Soft Body Actuated by Twi...

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International Conference on Mechatronics and Machine Vision in Practice (M2VIP)

作者： Dong Zhou Yuan Fu Jie Deng Jin Sun Yingxiang Liu State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin China

ISBN: (纸本)9781665431545

Soft robots made from soft materials can safely interact with humans and environments compared with the traditional rigid robots. However, the inherent compliance of the soft robots makes them difficult to realize the jumping motion. Although many soft robots can jump through the design of bistable structure. However, the existing soft robots need rigid spine to be embedded in the soft body. Therefore, it is still hard for the jumping of a soft robot with pure soft body. This paper offers the design method for the pure soft bistable robot with jumping ability. The critical buckling force and total elastic potential energy of the robot can be increased by designing the soft body with different thickness. We use the twisted artificial muscle (TAM) to realize the jumping motion of the soft bistable robot. The proposed robot can jump at a height nearly two times its body height. We envision that the design method will promote the application of the soft robot with pure soft body to realize more types of motion strategy.

关键词： Potential energy Fabrication Mechatronics Design methodology Machine vision Force Soft robotics

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Joint Limit Optimal Inverse Kinematics of the 7-DoF Manipulator with Link Offset based on Semi-analytical Solution

Joint Limit Optimal Inverse Kinematics of the 7-DoF Manipula...

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IEEE International Conference on robotics and Biomimetics

作者： Yaowen Zhang Yechao Liu Baoshi Cao Yang Liu Boyu Ma Zongwu Xie State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin China

ISBN: (纸本)9781665405362

The 7-DoF redundant manipulator with offset links and symmetrical structure is applied in the space station. The analytical solution of the inverse kinematics(IK) is difficult when considering the joint limits. This study proposes a joint limit optimal IK solution based on the optimization of the fixed joint angle parameters. The analytical method of fixed joint inverse solution is combined with the numerical method of joint limit optimization. This semi-analytical method converges to a definite solution with a closed form and have symmetry to avoid the non-conservative of the pseudo-inverse solution. Simulation results verify the effectiveness of the IK algorithm.

关键词： Jacobian matrices Simulation Conferences Kinematics Manipulators Search problems Orbits

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