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Understand anisotropy dependence of damage evolution and material removal during nanoscratch of MgF_(2) single crystals

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International Journal of Extreme Manufacturing 2023年第1期5卷 236-252页

作者： Chen Li Yinchuan Piao Feihu Zhang Yong Zhang Yuxiu Hu Yongfei Wang State Key Laboratory of Robotics and System(HIT) Harbin Institute of TechnologyHarbin 150001People’s Republic of China

To understand the anisotropy dependence of the damage evolution and material removal during the machining process of MgF_(2) single crystals,nanoscratch tests of MgF_(2) single crystals with different crystal planes and directions were systematically performed,and surface morphologies of the scratched grooves under different conditions were *** experimental results indicated that anisotropy considerably affected the damage evolution in the machining process of MgF_(2) single crystals.A stress field model induced by the scratch was developed by considering the anisotropy,which indicated that during the loading process,median cracks induced by the tensile stress initiated and propagated at the front of the *** cracks induced by tensile stress initiated and propagated on the subsurface during the unloading *** addition,surface radial cracks induced by the tensile stress were easily generated during the unloading *** stress change led to the deflection of the propagation direction of lateral ***,the lateral cracks propagated to the workpiece surface,resulting in brittle removal in the form of chunk *** plastic deformation parameter indicated that the more the slip systems were activated,the more easily the plastic deformation *** cleavage fracture parameter indicated that the cracks propagated along the activated cleavage planes,and the brittle chunk removal was owing to the subsurface cleavage cracks propagating to the crystal *** the same processing parameters,the scratch of the(001)crystal plane along the[100]crystal-orientation was found to be the most conducive to achieving plastic machining of MgF_(2) single *** theoretical results agreed well with the experimental results,which will not only enhance the understanding of the anisotropy dependence of the damage evolution and removal process during the machining of MgF_(2) crystals,but also provide a theoretical foundation for achiev

关键词： anisotropy dependence damage evolution stress field crack propagation nanoscratch MgF_(2)single crystal

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Hybrid Robotic Arm for Autonomous Aerial Refueling

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Chinese Journal of Mechanical Engineering 2024年第6期37卷 429-440页

作者： Kaixuan Li Gangfeng Liu Yongsheng Gao Jie Zhao State Key Laboratory of Robotics and Systems Harbin Institute of TechnologyHarbin 150080China School of Mechatronics Engineering Harbin 150080China

Autonomous aerial refueling technology is gaining increasing attention to enhance aircraft combat *** research on autonomous refueling focuses mainly on flight control laws,with little attention to the automation of refueling *** leads to high demands on control law performance and navigation accuracy,making it difficult to ensure *** address this,we propose a robotic arm system capable of automatic docking during the flexible aerial refueling *** system uses a conical kinematic space configuration,offering enhanced stability and impact *** frame-type structure achieves a lightweight ***,we establish a single-objective optimization model for the connecting rod dimensions and apply a genetic algorithm(GA)for their *** also propose a trajectory-fitting calibration theory based on the robotic arm's special configuration and complete its movement accuracy calibration using a laser *** calibration method reduces the robotic arm's motion error by 71%,achieving an absolute positioning accuracy better than 3.5 mm,which meets the requirements for autonomous aerial *** summary,this research presents a hybrid robotic arm that meets automatic docking requirements,offering a new approach to autonomous aerial refueling.

关键词： Autonomous aerial refueling Conical kinematic space configuration Optimization of structural design Calibration method

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Characterizing permeability-porosity relationships of porous rocks using a stress sensitivity model in consideration of elastic-structural deformation and tortuosity sensitivity

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第9期16卷 3437-3451页

作者： Ronghe Xu Liqin Wang Xiaoli Zhao Yuze Mao MIIT Key Laboratory of Aerospace Bearing Technology and Equipment Harbin Institute of TechnologyHarbin150001China State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin150001China Shanghai Aerospace Control Technology Institute Shanghai201100China

Clarifying the relationship between stress sensitivities of permeability and porosity is of great significance in guiding underground resource *** and more studies focus on how to construct stress sensitivity models to describe the relationship and obtain a comprehensive stress sensitivity of porous ***,the limitations of elastic deformation calculation and incompleteness of considered tortuosity sensitivity lead to the fact that the existing stress sensitivity models are still unsatisfactory in terms of accuracy and ***,a more accurate and generic stress sensitivity model considering elastic-structural deformation of capillary cross-section and tortuosity sensitivity is proposed in this *** elastic deformation is derived from the fractal scaling model and Hooke's *** the effects of elastic-structural deformation on tortuosity sensitivity,an empirical formula is proposed,and the conditions for its applicability are *** predictive performance of the proposed model for the permeability-porosity relationships is validated in several sets of publicly available experimental *** experimental data are from different rocks under different pressure *** mean and standard deviation of relative errors of predicted stress sensitivity with respect to experimental data are 2.63%and 1.91%.Compared with other models,the proposed model has higher accuracy and better predictive generalization *** is also found that the porosity sensitivity exponent a,which can describe permeability-porosity relationships,is 2 when only elastic deformation is considered.a decreases from 2 when structural deformation is also *** addition,a may be greater than 3 due to the increase in tortuosity sensitivity when tortuosity sensitivity is considered even if the rock is not fractured.

关键词： Stress sensitivity model Permeability-porosity relationships Elastic-structural deformation Tortuosity stress sensitivity

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Reorientation and obstacle avoidance control of free-floating modular robots using sinusoidal oscillator

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Chinese Journal of Aeronautics 2024年第6期37卷 262-275页

作者： Zhiyuan YANG Mingzhu LAI Jian QI Ning ZHAO Xin SUI Jie ZHAO Yanhe ZHU State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China School of Mathematics and Statistics Hainan Normal UniversityHaikou 571158China

This paper presents that a serpentine curve-based controller can solve locomotion control problems for articulated space robots with extensive flight phases,such as obstacle avoidance during free floating or attitude adjustment before *** proposed algorithm achieves articulated robots to use closed paths in the joint space to accomplish the above *** snakes,which can shuttle through gaps and adjust their landing posture by swinging their body during gliding in jungle environments,inspired the design of two *** first maneuver generates a rotation of the system by varying the moment of inertia between the joints of the robot,with the magnitude of the net rotation depending on the controller *** maneuver can be repeated to allow the robot to reach arbitrary *** second maneuver involves periodic undulations,allowing the robot to avoid collisions when the trajectory of the global Center of Mass(CM)passes through the *** maneuvers are based on the improved serpenoid curve,which can adapt to redundant systems consisting of different numbers of ***,the simulation illustrates that combining the two maneuvers can help a free-floating chain-type robot traverse complex *** proposed algorithm can be used with similar articulated robot models.

关键词： Collision avoidance Modularrobots Reorientation Free-floating space robots Nonholonomic systems Biologically inspired controllers Serpenoid curve

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Modelling and experimental investigation of micro-dimpled structures milling with spiral trajectory tool reciprocating motion

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Chinese Journal of Aeronautics 2025年第2期38卷 577-596页

作者： Guangzhou WANG Linjie ZHAO Qi LIU Xiguang LI Yazhou SUN Mingjun CHEN School of Mechatronics Engineering Harbin Institute of TechnologyHarbin 150001China Centre for Precision Manufacturing DMEMUniversity of StrathclydeGlasgow G11XJUK State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China

To mill fine and well-defined micro-dimpled structures,a machining manner of spiral trajectory tool reciprocating motion,where the tool repeats the process of‘feed milling–retract–cutting feed–feed milling again’along the spiral trajectory,was *** the kinematics analysis,it is found that the machining quality of micro-dimpled structures is highly dependent on the machining trajectory using spiral trajectory tool reciprocating *** reveal this causation,simulation modelling and experimental studies were carried out.A simulation model was developed to quantitatively and qualitatively investigate the influence of the trajectory discretization strategies(constant-angle and constant-arc length)and parameters(discrete angle,discrete arc length,and pitch)on surface texture and residual height of micro-dimpled ***,micro-dimpled structures were milled under different trajectory discretization strategies and parameters with spiral trajectory tool reciprocating motion.A comprehensive comparison between the milled results and simulation analysis was made based on geometry accuracy,surface morphology and surface roughness of milled ***,the errors and factors affecting the above three aspects were *** results demonstrate both the feasibility of the established simulation model and the machining capability of this machining way in milling high-quality micro-dimpled *** trajectory tool reciprocating motion provides a new machining way for milling micro-dimpled structures and micro-dimpled functional *** an appropriate machining trajectory can be generated based on the optimized trajectory parameters,thus contributing to the improvement of machining quality and efficiency.

关键词： Tool reciprocating motion Spiral trajectory Micro-dimpled structure Micromachining Simulation modelling with diamond tool Surface texture

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Towards understanding the surface rippling process by periodic reciprocal nanoscratching

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Friction 2023年第10期11卷 1815-1828页

作者： Zihan LI Yongda YAN Jiqiang WANG Chen LI Yanquan GENG State Key Laboratory of Robotics and Systems Robotics InstituteHarbin Institute of TechnologyHarbin 150080China Center for Precision Engineering Harbin Institute of TechnologyHarbin 150001China

The bundle structure formed perpendicular to the scratching direction is a type of wear-induced structure for *** this study,the formation mechanism of bundle structures on polycarbonate(PC)surfaces is investigated by reciprocal scratching *** on the analysis of the morphologies,friction forces,and height signals,the formation of the bundle structure is *** influence of scratching parameters,including the feed value and scratching direction,on the formation of the bundle structure is also *** is found that the bundle structure is accumulated by the continuous stacking of the sample materials plowed by the tip in stick–slip motion,and that the stick–slip behavior is enhanced with increased scratching *** work reproduces the formation process of bundle structure in experiments for the first time and demonstrates that the stick–slip enhancement mechanism exists in the reciprocal scratching process,providing further insight into the friction behavior of polymers.

关键词： atomic force microscopy(AFM) bundle structures stick-slip friction force

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Temperature field characteristics of CF/PEEK thermoplastic composites formed by automated fiber placement using hot gas torch with slit structure nozzle

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Chinese Journal of Aeronautics 2024年第6期37卷 392-409页

作者： Ziang JIN Shouzheng SUN Sunil Chandrakant JOSHI Zhenyu HAN Hongya FU State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China School of Mechanical and Aerospace Engineering Nanyang Technological UniversitySingapore 639798Singapore

In-situ consolidation forming of high-performance thermoplastic composites by Automated Fiber Placement(AFP)is of significant interest in *** the laying process,the heating temperature has a great influence on the quality of the formed components.A threedimensional heat transfer finite element model of Carbon Fiber(CF)/Polyether Ether Ketone(PEEK)heated by Slit Structure Nozzle Hot Gas Torch(SSNHGT)assisted AFP is *** influence of gas flow rate,heat transfer distance,and laying speed on heating temperature is *** results show that the overall temperature increases and then decreases as the gas flow rate *** the increase in heat transfer distance and laying speed,the overall temperature ***,the gas flow rate has the greatest influence on the temperature of CF/PEEK being heated,followed by the laying speed and finally the heat transfer ***,the model can also be extended to other fiber-reinforced polymer composites formed by hot gas torch assisted AFP,which can guide the optimization of process parameters for subsequent heating temperature control.

关键词： Fiber reinforced plastics Thermoplastics Heating temperature Automated fiber placement CF/PEEK

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Review on Development of Automatic Docking system for Weapons and Cabins

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Recent Patents on Engineering 2024年第2期18卷 63-87页

作者： Tang, Dedong Cheng, Chao Quan, Qiquan Deng, Zongquan Liu, Hao Key Laboratory of Advanced Manufacturing and Intelligent Technology Ministry of Education Harbin University of Science and Technology Harbin150080 China State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin150001 China

Background: In the manufacturing setup process of weapons, aviation, and aerospace, docking assembly is a key component in determining manufacturing efficiency and quality. The traditional docking method uses manual alignment, which depends on the experience and operation level of the workers, so the docking accuracy is low and the installation speed is slow. In response to this problem, how to achieve automatic docking of weapons and cabins has become a key technology. Objective: The objective of this study is to provide an overview of recent key technologies for automatic docking systems and introduce their respective classification, characteristics, and development. Methods: This paper reviews the patents and products related to the key technologies of automatic docking systems. The structural features, methodological principles, control characteristics and applications of the patents and products are summarized. Results: The key technologies related to different aspects of an automatic docking system are compared and analyzed, and the structural features, and methodological principles are also summarized. The problems of the current key technologies are analyzed, and the current status of research and future directions of the automatic docking system are discussed. Conclusion: According to the key technologies related to different aspects of the automatic docking system, they can be divided into motion mechanism, pose detection technology, and computer control technology. The accuracy, compliance, and flexibility of the automatic docking system can be improved by choosing the proper key technology. Further improvements are needed in terms of fast performance, robustness and authenticity, and more patents on key technologies of automatic docking systems should be invented. © 2024 Bentham Science Publishers.

关键词： Patents and inventions

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An efficient stiffness analysis model based on shear deformation theory for flexible skin shear variable-sweep wing

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Chinese Journal of Aeronautics 2024年第10期37卷 445-458页

作者： Yue BAI Guang YANG Hong XIAO Hongwei GUO Rongqiang LIU Bei LIU State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China China Aerodynamics Research and Development Center Institute of High-Speed AerodynamicsMianyang 621000China

Fixed-wing aircraft cannot maintain optimal aerodynamic performance at different flight speeds. As a type of morphing aircraft, the shear variable-sweep wing(SVSW) can dramatically improve its aerodynamic performance by altering its shape to adapt to various flight *** order to achieve smooth continuous shear deformation, SVSW's skin adopts a flexible composite skin design instead of traditional aluminum alloy materials. However, this also brings about the non-linear difficulty in stiffness modeling and calculation. In this research, a new SVSW design and efficient stiffness modeling method are proposed. Based on shear deformation theory, the flexible composite skin is equivalently modeled as diagonally arranged nonlinear springs, simulating the elastic force interaction between the skin and the mechanism. By shear loading tests of flexible composite skin, the accuracy of this flexible composite skin modeling method is verified. The SVSW stiffness model was established, and its accuracy was verified through static loading tests. The effects of root connection, sweep angles, and flexible composite skin on the SVSW stiffness are analyzed. Finally, considering three typical flight conditions of SVSW: low-speed flow(Ma = 0.3,Re = 5.82 × 10^(6)), transonic flow(Ma = 0.9, Re = 3.44 × 10^(6)), and supersonic flow(Ma = 3,Re = 7.51 × 10^(6)), the stiffness characteristics of SVSW under flight conditions were *** calculated results guide the application of SVSW.

关键词： Shear variable-sweep wing(SVSW) Flexible composite skin Morphing mechanism Stiffness analysis Loading tests Structure

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A Rhythmic Motion Control Method Inspired by Board Shoe Racing for a Weight-Bearing Exoskeleton

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Journal of Bionic Engineering 2022年第2期19卷 403-415页

作者： Tianshuo Wang Jie Zhao Dongbao Sui Sikai Zhao Yanhe Zhu State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China

To ensure the flexible walking of the weight-bearing exoskeleton robot,most researchers control the exoskeleton to follow the wearer’s movements and provide force to maintain the current dynamic ***,due to the limitation of sensing information and computing power,it is difficult for the exoskeleton to provide the wearer reasonable and stable force only based on the dynamic model,especially in switching between swing phase and stance *** by China’s traditional sport named board shoe racing,a walking control method based on the cooperation of the human and the exoskeleton is proposed in this paper for a lower-limb exoskeleton named *** certain conditions,the exoskeleton itself can walk stably depending on the rhythm signals generated by the Central Pattern Generator(CPG).With certain initiative during walking,it can make proper adjustments according to the human *** the help of dynamic simulation software and Genetic Algorithm(GA),the optimized CPG parameters are *** control is introduced to increase the comfort of the *** impedance parameters as well as the CPG parameters are tuned in real time based on *** experiments were conducted with *** results demonstrate that PALExo can effectively assist the wearer walking with a 45-kg payload benefiting from the proposed method.

关键词： Exoskeleton robot Central pattern generator Walking control method

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