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Inverted Modelling:An Effective Way to Support Motion Planning of Legged Mobile Robots

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Chinese Journal of Mechanical Engineering 2023年第1期36卷 268-279页

作者： Chenyao Zhao weizhong guo State Key Laboratory of Mechanical Systems and Vibration School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai200240China

This paper presents an effective way to support motion planning of legged mobile robots—Inverted Modelling,based on the equivalent metamorphic mechanism concept.The difference from the previous research is that we herein invert the equivalent parallel mechanism.Assuming the leg mechanisms are hybrid links,the body of robot being considered as fixed platform,and ground as moving platform.The motion performance is transformed and measured in the body frame.Terrain and joint limits are used as input parameters to the model,resulting in the representation which is independent of terrains and particular poses in Inverted Modelling.Hence,it can universally be applied to any kind of legged robots as global motion performance framework.Several performance measurements using Inverted Modelling are presented and used in motion performance evaluation.According to the requirements of actual work like motion continuity and stability,motion planning of legged robot can be achieved using different measurements on different terrains.Two cases studies present the simulations of quadruped and hexapod robots walking on rugged roads.The results verify the correctness and effectiveness of the proposed method.

关键词： Gait planning Inverted Modelling Legged mobile robot Motion planning Workspace

Design of A Novel Wheel-Legged Robot with Rim Shape Changeable Wheels

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Chinese Journal of Mechanical Engineering 2023年第6期36卷 62-72页

作者： Ze Fu Hao Xu Yinghui Li weizhong guo State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China

The wheel-legged hybrid structure has been utilized by ground mobile platforms in recent years to achieve good mobility on both flat surfaces and rough terrain.However,most of the wheel-legged robots only have one-directional obstacle-crossing ability.During the motion,most of the wheel-legged robots’centroid fluctuates violently,which damages the stability of the load.What’s more,many designs of the obstacle-crossing part and transformation-driving part of this structure are highly coupled,which limits its optimal performance in both aspects.This paper presents a novel wheel-legged robot with a rim-shaped changeable wheel,which has a bi-directional and smooth obstacle-crossing ability.Based on the kinematic model,the geometric parameters of the wheel structure and the design variables of the driving four-bar mechanism are optimized separately.The kinetostatics model of the mobile platform when climbing stairs is established to determine the body length and angular velocity of the driving wheels.A pro-totype is made according to the optimal parameters.Experiments show that the prototype installed with the novel transformable wheels can overcome steps with a height of 1.52 times of its wheel radius with less fluctuation of its centroid and performs good locomotion capabilities in different environments.

关键词： Mobile platform Transformable wheel-legged robot Kinematics analysis Mechanical design Obstacle

Conceptual design and analysis of legged landers with orientation capability

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Chinese Journal of Aeronautics 2023年第3期36卷 171-183页

作者： Rongfu LIN weizhong guo Changjie ZHAO Mingda HE State Key Laboratory of Mechanical System and Vibration School of Mechanical EngineeringShanghai Jiao Tong University200240China

The lander with orientation capability is of fundamental importance for the“Returning”mission because its body can be the base with a suitable launching angle for the ascender lifting off.This paper proposes the conceptual design and verification of Landers with Orientation Capability(LOCs).Firstly,the topological composition of the lander is analyzed and expressed in the form of Lie group,which provides the fundamental principle for the type synthesis of LOCs.Then,the type synthesis approach for designing LOCs is proposed,which includes designing the Equivalent Parallel Mechanism(EPM)and the auxiliary limbs.Numerous mechanisms of LOCs with twodimensional rotational motions are obtained based on the type synthesis approach by developing and combining the EPMs and auxiliary limbs.Afterward,kinematics and Jacobian matrix of a typical legged lander are developed,the workspace is analyzed,singularity configurations are analyzed based on the wrench graph method,and finally,the orientation capability is analyzed.The pitch and yaw angle reach 17.5°,considering the permissible range of joints.The proposed types of LOCs offer potential candidate for the“Returning”mission of the exploration mission.

关键词： Legged lander Orientation analysis Orientation capability Parallel mechanism Type synthesis

NuBot:A Magnetic Adhesion Robot with Passive Suspension to Inspect the Steel Lining

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Chinese Journal of Mechanical Engineering 2023年第3期36卷 161-178页

作者： Hao Xu Youcheng Han Mingda He Yinghui Li weizhong guo State Key Lab of Mechanical System and Vibration School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China

The steel lining of huge facilities is a significant structure,which experiences extreme environments and needs to be inspected periodically after manufacture.However,due to the complexity(crisscross welds,curved surface,etc.)of their inside environments,high demands for stable adhesion and curvature adaptability are put forward.This paper presents a novel wheeled magnetic adhesion robot with passive suspension applied in nuclear power containment called NuBot,and mainly focuses on the following aspects:(1)proposing the wheeled locomotion suspension to adapt the robot to the uneven surface;(2)implementing the parameter optimization of NuBot.A comprehensive optimization model is established,and global optimal dimensions are properly chosen from performance atlases;(3)determining the normalization factor and actual dimensional parameters by constraints of the steel lining environment;(4)structure design of the overall robot and the magnetic wheels are completed.Experiments show that the robot can achieve precise locomotion on both strong and weak magnetic walls with various inclination angles,and can stably cross the 5 mm weld seam.Besides,its maximum payload capacity reaches 3.6 kg.Results show that the NuBot designed by the proposed systematic method has good comprehensive capabilities of surface-adaptability,adhesion stability,and payload.Besides,the robot can be applied in more ferromagnetic environments and the design method offers guidance for similar wheeled robots with passive suspension.

关键词： Wheeled robot Passive suspension Magnetic adhesion Steel lining Design method

Task-Oriented Topology System Synthesis of Reconfigurable Legged Mobile Lander Integrating Active and Passive Metamorphoses

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Chinese Journal of Mechanical Engineering 2023年第3期36卷 89-109页

作者： Youcheng Han Ziyue Li Gaohan Zhu weizhong guo Jianzhong Yang Wei Liu State Key Lab of Mechanical System and Vibration School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China Beijing Institute of Spacecraft System Engineering Beijing 100094China

To explore hostile extraterrestrial landforms and construct an engineering prototype,this paper presents the task-oriented topology system synthesis of reconfigurable legged mobile lander(ReLML)with three operation modes from adjusting,landing,to roving.Compared with our preceding works,the adjusting mode with three rotations(3R)provides a totally novel exploration approach to geometrically matching and securely arriving at complex terrains dangerous to visit currently;the landing mode is redefined by two rotations one translation(2R1T),identical with the tried-and-tested Apollo and Chang'E landers to enhance survivability via reasonable touchdown buffering motion;roving mode also utilizes 2R1T motion for good motion and force properties.The reconfigurable mechanism theory is first brought into synthesizing legged mobile lander integrating active and passive metamorphoses,composed of two types of metamorphic joints and metamorphic execution and transmission mechanisms.To reveal metamorphic principles with multiple finite motions,the finite screw theory is developed to present the procedure from unified mathematical representation,modes and source phase derivations,metamorphic joint and limb design,to final structure assembly.To identify the prototype topology,the 3D optimal selection matrix method is proposed considering three operation modes,five evaluation criteria,and two topological subsystems.Finally,simulation verifies the whole task implementation process to ensure the reasonability of design.

关键词： Legged mobile lander Topology synthesis Active and passive metamorphoses Finite screw Metamorphic joint Reconfigurable mechanism

Modeling and Configuration Design of Electromagnetic Actuation Coil for a Magnetically Controlled Microrobot

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Chinese Journal of Mechanical Engineering 2019年第4期32卷 13-25页

作者： Xiaolong Jing weizhong guo Institute of Design and Control Engineering for Heavy Equipment School of Mechanical Engineering Shanghai Jiao Tong University

Non-contact actuated microbeads have attracted a lot of attention in recent years because of its enormous potential in medical, biological, and industrial applications. Researchers have proposed a multitude of electromagnetic actuation(EMA) systems consisting of a variety of coil pairs. However, a unified method to design and optimize a coil pair according to technical specifications still does not exist. Initially, this paper presented the modeling of an untethered ferromagnetic particle actuated by externally applied magnetic field. Based on the models, a simple method of designing and optimizing the EMA coil pair according to technical specifications, was proposed. A loop-shaped coil pair generating uniform magnetic and gradient fields was chosen to demonstrate this method clearly and practically. The results of the optimization showed that the best distance to radius ratio of a loop-shaped coil pair is 1.02 for a uniform magnetic field and 1.75 for a uniform gradient field. The applicability of the method to other shapes of coil configuration was also illustrated. The best width to distance ratio for a square-shaped coil pair is 0.558 and 0.958 for uniform magnetic and gradient fields, respectively. The best height to width ratio and distance to width ratio for a rectangle-shaped coil pair is h/w =[0.9,1.1], d/w =[0.5,0.6] for uniform magnetic field and h/w =[1.0,1.2], d/w =[0.9,1.1] for uniform gradient field. Furthermore, simulations of a microparticle tracking the targeted trajectory were conducted to analyze the performance of the newly designed coils. The simulations suggested the ability of manipulating microparticles via the coils designed by our proposed method. The research mainly proposed a unified design and optimization method for a coil pair, which can support researchers while designing a specific coil pair according to the technical requirements. This study is aimed at researchers who are interested in EMA system and microrobots.

关键词： Micro-robot/particle Coil configuration design and optimization Electromagnetic actuation Trajectory tracking

Ag/Al_(2)O_(3)对船舶发动机尾气HC与NO_(x)协同催化净化

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内燃机学报 2024年第2期42卷 144-152页

作者：杨新伟郭江峰周伟中沪东重机有限公司上海201206 中船动力(集团)有限公司上海201208

船舶发动机尾气中的氮氧化物(NO_(x))和碳氢化合物(HC)对大气环境有较大的危害.直接利用HC作为还原剂与NO_(x)发生选择性催化还原脱硝反应(HC-SCR),实现对发动机尾气中的HC和NO_(x)协同催化净化,是非常具有应用前景的船舶尾气净化技术之... 详细信息

船舶发动机尾气中的氮氧化物(NO_(x))和碳氢化合物(HC)对大气环境有较大的危害.直接利用HC作为还原剂与NO_(x)发生选择性催化还原脱硝反应(HC-SCR),实现对发动机尾气中的HC和NO_(x)协同催化净化,是非常具有应用前景的船舶尾气净化技术之一,而开发高性能的HC-SCR催化剂是该技术的核心.采用商业伽马型氧化铝(γ-Al_(2)O_(3))作为载体、硝酸银(AgNO_(3))作为前驱体,通过湿浸渍法制备了负载型银基氧化铝(Ag/Al_(2)O_(3))催化剂.经固定床反应器活性测试发现,纯γ-Al_(2)O_(3)载体在甲烷-SCR(CH_(4)-SCR)和丙烷-SCR(C_(3)H_(8)-SCR)中具有一定的催化活性,而负载银(Ag)后得到的催化剂(Ag/Al_(2)O_(3))在反应中的低温催化性能得到进一步提高.利用粉末X射线衍射技术(XRD)、紫外可见分光光谱(UV-Vis)、HC完全氧化、NO_(x)程序升温脱附(NO-O_(2)-TPD)及原位红外光谱(in situ DRIFTS)等表征手段,分析了Ag/Al_(2)O_(3)催化剂的主要物相组成以及Ag物种的状态,并详细阐述了Ag/Al_(2)O_(3)催化剂表面HC-SCR反应的反应路径,即:HC在催化剂表面Ag物种的作用下部分氧化形成活性中间体醋酸类物种;一氧化氮(NO)在催化剂载体表面吸附活化成单齿硝酸盐类物种;HC部分氧化中间体醋酸类物种与NO吸附活化物种单齿硝酸盐物种发生反应,生成氮气(N2)和水(H2O).

关键词：船舶发动机氮氧化物碳氢选择性催化还原

基于图像处理判断水混凝中矾花性能的研究及应用进展

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热力发电 2024年第5期53卷 1-9页

作者：郭上科郭俊文文昌璧李博润滕维忠江小伟章德才乔越华能海南发电股份有限公司东方电厂海南东方572633 西安热工研究院有限公司陕西西安710054

原水预处理主要分为混凝、沉淀和过滤3个阶段,混凝中的絮凝过程直接影响矾花结构与出水浊度;目前多采用检测出水浊度方法来控制混凝剂加药量,但因时间滞后无法快速反映混凝效果与反馈调节加药量。随着计算机技术的快速发展,利用矾花图... 详细信息

原水预处理主要分为混凝、沉淀和过滤3个阶段,混凝中的絮凝过程直接影响矾花结构与出水浊度;目前多采用检测出水浊度方法来控制混凝剂加药量,但因时间滞后无法快速反映混凝效果与反馈调节加药量。随着计算机技术的快速发展,利用矾花图像处理技术能够实现快速、准确、实时检测絮凝状态,从而更准确控制加药量,提高混凝效果。从计算机视觉技术角度,概述了絮凝中矾花图像采集与处理的技术特点,介绍了实时跟踪和计算矾花结构特征参数如等效粒径、分形维数等方法,并给出了部分试验结果,通过这些参数可以判断最佳混凝效果,为混凝控制与加药提供依据。

关键词：絮凝矾花图像处理等效粒径分形维数

维普期刊数据库博看期刊

Low-temperature catalytic combustion of trichloroethylene over MnO_(x)-CeO_(2)mixed oxide catalysts

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稀土学报：英文版 2023年第4期41卷 523-530页

作者： Kai Shen Mingxiang Jiang Xinwei Yang weizhong Zhou Qiguang Dai Xingyi Wang Li Wang Yun guo Yanglong guo Wangcheng Zhan Key Laboratory for Advanced Materials Research Institute of Industrial CatalysisSchool of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China Hudong Heavy Machinery Co. Ltd.Shanghai 200237China

The cerium-based catalysts were investigated for the catalytic co mbustion of trichlo roethylene(TCE)and exhibit a surprising catalytic activity.MnO_(x)was doped into CeO_(2)by a citric acid(CA)sol-gel method,and the effect of Mn content on the physicochemical properties and catalytic activities of MnO_(x)-CeO_(2)mixed oxides was investigated systemically.The introduction of MnO_(x)into CeO_(2)can evidently improve the catalytic activity and reaction stability of the CeO_(2)catalyst,and the catalytic activity can be maintained for more than 100 h at 250℃under air atmosphere.Moreover,a possible reaction mechanism and a catalytic cycle for the catalytic combustion of TCE over the MnO_(x)-CeO_(2)mixed oxide catalysts are proposed.

关键词： Catalytic combustion Trichloroethylene Cerium oxide Manganese oxide Rare Earths