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Design of a novel side-mounted leg mechanism with high flexibility for a multi-mission quadruped earth

《机械工程前沿（英文）》 2023年 第18卷 第2期 doi: 10.1007/s11465-022-0740-0

摘要： Earth rover is a class of emerging wheeled-leg robots for nature exploration. At present, few methods for these robots’ leg design utilize a side-mounted spatial parallel mechanism. Thus, this paper presents a complete design process of a novel 5-degree-of-freedom (5-DOF) hybrid leg mechanism for our quadruped earth rover BJTUBOT. First, a general approach is proposed for constructing the novel leg mechanism. Subsequently, by evaluating the basic locomotion task (LT) of the rover based on screw theory, we determine the desired motion characteristic of the side-mounted leg and carry out its two feasible configurations. With regard to the synthesis method of the parallel mechanism, a family of concise hybrid leg mechanisms using the 6-DOF limbs and an L1F1C limb (which can provide a constraint force and a couple) is designed. In verifying the motion characteristics of this kind of leg, we select a typical (3-UPRU&RRRR)&R mechanism and then analyze its kinematic model, singularities, velocity mapping, workspace, dexterity, statics, and kinetostatic performance. Furthermore, the virtual quadruped rover equipped with this innovative leg mechanism is built. Various basic and specific LTs of the rover are demonstrated by simulation, which indicates that the flexibility of the legs can help the rover achieve multitasking.

关键词： design synthesis     parallel mechanism     hybrid leg mechanism     screw theory     quadruped robot    

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Operation analysis of a Chebyshev-Pantograph leg mechanism for a single DOF biped robot

Conghui LIANG, Marco CECCARELLI, Yukio TAKEDA

《机械工程前沿（英文）》 2012年 第7卷 第4期   页码 357-370 doi: 10.1007/s11465-012-0340-5

摘要：

In this paper, operation analysis of a Chebyshev-Pantograph leg mechanism is presented for a single degree of freedom (DOF) biped robot. The proposed leg mechanism is composed of a Chebyshev four-bar linkage and a pantograph mechanism. In contrast to general fully actuated anthropomorphic leg mechanisms, the proposed leg mechanism has peculiar features like compactness, low-cost, and easy-operation. Kinematic equations of the proposed leg mechanism are formulated for a computer oriented simulation. Simulation results show the operation performance of the proposed leg mechanism with suitable characteristics. A parametric study has been carried out to evaluate the operation performance as function of design parameters. A prototype of a single DOF biped robot equipped with two proposed leg mechanisms has been built at LARM (Laboratory of Robotics and Mechatronics). Experimental test shows practical feasible walking ability of the prototype, as well as drawbacks are discussed for the mechanical design.

关键词： biped robots     leg mechanisms     simulation    

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Design method and verification of a hybrid prosthetic mechanism with energy-damper clutchable device

《机械工程前沿（英文）》 2021年 第16卷 第4期   页码 747-764 doi: 10.1007/s11465-021-0644-4

摘要： Transfemoral amputees (TAs) have difficulty in mobility during walking, such as restricted movement of lower extremity and body instability, yet few transfemoral prostheses have explored human-like multiple motion characteristics by simple structures to fit the kinesiology, biomechanics, and stability of human lower extremity. In this work, the configurations of transfemoral prosthetic mechanism are synthesized in terms of human lower-extremity kinesiology. A hybrid transfemoral prosthetic (HTP) mechanism with multigait functions is proposed to recover the gait functions of TAs. The kinematic and mechanical performances of the designed parallel mechanism are analyzed to verify their feasibility in transfemoral prosthetic mechanism. Inspired by motion–energy coupling relationship of the knee, a wearable energy-damper clutched device that can provide energy in knee stance flexion to facilitate the leg off from the ground and can impede the leg’s swing velocity for the next stance phase is proposed. Its co-operation with the springs in the prismatic pairs enables the prosthetic mechanism to have the energy recycling ability under the gait rhythm of the knee joint. Results demonstrate that the designed HTP mechanism can replace the motion functions of the knee and ankle to realize its multimode gait and effectively decrease the peak power of actuators from 94.74 to 137.05 W while maintaining a good mechanical adaptive stability.

关键词： hybrid transfemoral prosthetic mechanism     energy recycling     wearable mechanical clutched device     mechanical adaptive stability    

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Load-sharing mechanism in timber-steel hybrid shear wall systems

Zheng LI,Minjuan HE,Frank LAM,Minghao LI

《结构与土木工程前沿（英文）》 2015年 第9卷 第2期   页码 203-214 doi: 10.1007/s11709-015-0293-y

摘要： The lateral performance of timber-steel hybrid shear wall systems with regard to the interaction between the steel frame and the infill wood shear wall was investigated in this paper. A numerical model for the timber-steel hybrid shear wall system was developed and verified against test results. Design parameters, such as the lateral infill-to-frame stiffness ratio and the arrangements of wood-steel bolted connections were studied using the numerical model. Some design recommendations were also proposed based on the parametric analysis. In the hybrid shear wall system, the infill wood wall was found to resist a major part of the lateral load within relatively small wall drifts, and then the steel frame provided more lateral resistance. Under seismic loads, the infill wood wall could significantly reduce the inter-story drift of the hybrid system, and a complementary effect between the infill wood wall and the steel frame was observed through different lateral load resisting mechanisms, which provided robustness to the hybrid shear wall systems.

关键词： timer-steel hybrid     shear wall     load sharing mechanism     seismic performance     parametric analysis    

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Hybrid forming mechanism of patternless casting and laser cladding

Zhongde SHAN, Fuzhen SUN, Yang LIU

《机械工程前沿（英文）》 2019年 第14卷 第4期   页码 393-401 doi: 10.1007/s11465-019-0550-1

摘要： In accordance with the requirement of manufacturing dies quickly and economically, a hybrid forming method of stamping dies for automobile panels is proposed. The method combines digital patternless casting and high-power laser cladding. An experimental study is conducted on the hybrid forming process and its trial production and application in the manufacturing of stamping dies for typical panels. Results prove that the laser cladding layer exceeds HRC60 (Rockwell hardness) and thus meets the production efficiency requirement of automobile dies. The rate of defects is well controlled. Compared with traditional technology, this technology has remarkable advantages and advancement.

关键词： patternless casting     laser cladding     hybrid forming     rapid tooling    

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Different manipulation mode analysis of a radial symmetrical hexapod robot with leg–arm integration

《机械工程前沿（英文）》 2022年 第17卷 第1期   页码 8-8 doi: 10.1007/s11465-021-0664-0

摘要： With the widespread application of legged robot in various fields, the demand for a robot with high locomotion and manipulation ability is increasing. Adding an extra arm is a useful but general method for a legged robot to obtain manipulation ability. Hence, this paper proposes a novel hexapod robot with two integrated leg–arm limbs that obtain dexterous manipulation functions besides locomotion ability without adding an extra arm. The manipulation modes can be divided into coordinated manipulation condition and single-limb manipulation condition. The former condition mainly includes fixed coordinated clamping case and fixed coordinated shearing case. For the fixed coordinated clamping case, the degrees of freedom (DOFs) analysis of equivalent parallel mechanism by using screw theory and the constraint equation of two integrated limbs are established. For the fixed coordinated shearing case, the coordinated working space is determined, and an ideal coordinated manipulation ball is presented to guide the coordinated shearing task. In addition, the constraint analysis of two adjacent integrated limbs is performed. Then, mobile manipulation with one integrated leg–arm limb while using pentapod gait is discussed as the single-limb manipulation condition, including gait switching analysis between hexapod gait and pentapod gait, different pentapod gaits analysis, and a complex six-DOF manipulation while walking. Corresponding experiments are implemented, including clamping tasks with two integrated limbs, coordinated shearing task by using two integrated limbs, and mobile manipulation with pentapod gait. This robot provides a new approach to building a multifunctional locomotion platform.

关键词： leg–arm integration     hexapod robot     fixed coordinated manipulation     mobile manipulation    

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A feasibility study on the design and walking operation of a biped locomotor via dynamic simulation

null

《机械工程前沿（英文）》 2016年 第11卷 第2期   页码 144-158 doi: 10.1007/s11465-016-0391-0

摘要：

A feasibility study on the mechanical design and walking operation of a Cassino biped locomotor is presented in this paper. The biped locomotor consists of two identical 3 degrees-of-freedom tripod leg mechanisms with a parallel manipulator architecture. Planning of the biped walking gait is performed by coordinating the motions of the two leg mechanisms and waist. A three-dimensional model is elaborated in SolidWorks® environment in order to characterize a feasible mechanical design. Dynamic simulation is carried out in MSC.ADAMS® environment with the aims of characterizing and evaluating the dynamic walking performance of the proposed design. Simulation results show that the proposed biped locomotor with proper input motions of linear actuators performs practical and feasible walking on flat surfaces with limited actuation and reaction forces between its feet and the ground. A preliminary prototype of the biped locomotor is built for the purpose of evaluating the operation performance of the biped walking gait of the proposed locomotor.

关键词： feasibility study     biped locomotor     biped walking     mechanical design     dynamic simulation     tripod leg mechanism     3-UPU parallel manipulator    

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pyrolysis to convert biomass to versatile 3D carbon nanotubes/mesoporous carbon architecture: conversion mechanism

《化学科学与工程前沿（英文）》 2023年 第17卷 第6期   页码 679-690 doi: 10.1007/s11705-022-2266-8

摘要： The massive conversion of resourceful biomass to carbon nanomaterials not only opens a new avenue to effective and economical disposal of biomass, but provides a possibility to produce highly valued functionalized carbon-based electrodes for energy storage and conversion systems. In this work, biomass is applied to a facile and scalable one-step pyrolysis method to prepare three-dimensional (3D) carbon nanotubes/mesoporous carbon architecture, which uses transition metal inorganic salts and melamine as initial precursors. The role of each employed component is investigated, and the electrochemical performance of the attained product is explored. Each component and precise regulation of their dosage is proven to be the key to successful conversion of biomass to the desired carbon nanomaterials. Owing to the unique 3D architecture and integration of individual merits of carbon nanotubes and mesoporous carbon, the as-synthesized carbon nanotubes/mesoporous carbon hybrid exhibits versatile application toward lithium-ion batteries and Zn-air batteries. Apparently, a significant guidance on effective conversion of biomass to functionalized carbon nanomaterials can be shown by this work.

关键词： biomass     direct pyrolysis     3D CNTs/MC hybrid     lithium-ion batteries     Zn-air batteries    

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Performance investigation of artificial intelligence based controller for three phase four leg shunt

J. JAYACHANDRAN,R. MURALI SACHITHANANDAM

《能源前沿（英文）》 2015年 第9卷 第4期   页码 446-460 doi: 10.1007/s11708-015-0378-2

摘要： In this paper, the choice of power quality compensator is a DSTATCOM which constitutes a three phase four leg voltage source converter (VSC) with a DC capacitor. The control strategy proposed for the DSTATCOM is a neural network based one cycle control (OCC). This control strategy involves neural network block, digital circuits and linear elements, which eliminates the sensors required for sensing the load current and coupling inductor current in addition to the multiplier employed in the conventional method. The calculation of harmonic and reactive currents for the reference current generation is also eliminated, thus minimizing the complexity in the control strategy. The control strategy mitigates harmonic/reactive currents, ensures balanced and sinusoidal source current from the supply mains that are nearly in phase with the supply voltage, compensates neutral current, and maintains voltage across the capacitor under unbalanced source and load conditions. The performance of the DSTATCOM with the proposed artificial neural network (ANN) controllers is validated and investigated through simulations using Matlab software. The simulation results prove the efficacy of the proposed neural network based control strategy under varying source and load conditions.

关键词： neural network     DSTATCOM     neutral current mitigation     total harmonic distortion (THD)     three phase four wire distribution system     unbalanced and/or distorted source    

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Intelligent hybrid power generation system using new hybrid fuzzy-neural for photovoltaic system and

Alireza REZVANI,Ali ESMAEILY,Hasan ETAATI,Mohammad MOHAMMADINODOUSHAN

《能源前沿（英文）》 2019年 第13卷 第1期   页码 131-148 doi: 10.1007/s11708-017-0446-x

摘要： Photovoltaic (PV) generation is growing increasingly fast as a renewable energy source. Nevertheless, the drawback of the PV system is intermittent because of depending on weather conditions. Therefore, the wind power can be considered to assist for a stable and reliable output from the PV generation system for loads and improve the dynamic performance of the whole generation system in the grid connected mode. In this paper, a novel topology of an intelligent hybrid generation system with PV and wind turbine is presented. In order to capture the maximum power, a hybrid fuzzy-neural maximum power point tracking (MPPT) method is applied in the PV system. The average tracking efficiency of the hybrid fuzzy-neural is incremented by approximately two percentage points in comparison with the conventional methods. The pitch angle of the wind turbine is controlled by radial basis function network-sliding mode (RBFNSM). Different conditions are represented in simulation results that compare the real power values with those of the presented methods. The obtained results verify the effectiveness and superiority of the proposed method which has the advantages of robustness, fast response and good performance. Detailed mathematical model and a control approach of a three-phase grid-connected intelligent hybrid system have been proposed using Matlab/Simulink.

关键词： photovoltaic     wind turbine     hybrid system     fuzzy logic controller     genetic algorithm     RBFNSM    

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Robust ensemble of metamodels based on the hybrid error measure

《机械工程前沿（英文）》 2021年 第16卷 第3期   页码 623-634 doi: 10.1007/s11465-021-0641-7

摘要： Metamodels have been widely used as an alternative for expensive physical experiments or complex, time-consuming computational simulations to provide a fast but accurate analysis. However, challenge remains in the prior determination of the most suitable metamodel for a particular case because of the lack of information about the actual behavior of a system. In addition, existing studies on metamodels have largely restricted on solving deterministic problems (e.g., data from finite element models), whereas some real-life engineering problems (e.g., data from physical experiment) are stochastic problems with noisy data. In this work, a robust ensemble of metamodels (EMs) is proposed by combining three regression stand-alone metamodels in a weighted sum form. The weight factor is adaptively determined according to the hybrid error metric, which combines global and local error measures to improve the accuracy of the EMs. Furthermore, three typical individual metamodels that can filter noise are selected to construct the EMs to extend their application in practical engineering problems. Three well-known benchmark problems with different levels of noise and three engineering problems are used to verify the effectiveness of the proposed EMs. Results show that the proposed EMs have higher accuracy and robustness than the individual metamodels and other typical EMs in major cases.

关键词： metamodel     ensemble of metamodels     hybrid error measure     stochastic problem    

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Diffusion process in enzyme–metal hybrid catalysts

《化学科学与工程前沿（英文）》 2022年 第16卷 第6期   页码 921-929 doi: 10.1007/s11705-022-2144-4

摘要： Enzyme–metal hybrid catalysts bridge the gap between enzymatic and heterogeneous catalysis, which is significant for expanding biocatalysis to a broader scope. Previous studies have demonstrated that the enzyme–metal hybrid catalysts exhibited considerably higher catalytic efficiency in cascade reactions, compared with that of the combination of separated enzyme and metal catalysts. However, the precise mechanism of this phenomenon remains unclear. Here, we investigated the diffusion process in enzyme–metal hybrid catalysts using Pd/lipase-Pluronic conjugates and the combination of immobilized lipase (Novozyme 435) and Pd/C as models. With reference to experimental data in previous studies, the Weisz–Prater parameter and efficiency factor of internal diffusion were calculated to evaluate the internal diffusion limitations in these catalysts. Thereafter, a kinetic model was developed and fitted to describe the proximity effect in hybrid catalysts. Results indicated that the enhanced catalytic efficiency of hybrid catalysts may arise from the decreased internal diffusion limitation, size effect of Pd clusters and proximity of the enzyme and metal active sites, which provides a theoretical foundation for the rational design of enzyme–metal hybrid catalysts.

关键词： enzyme–metal hybrid catalyst     internal diffusion     proximity effect     kinetic model    

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Powertrain control of a solar photovoltaic-battery powered hybrid electric vehicle

P. PADMAGIRISAN, V. SANKARANARAYANAN

《能源前沿（英文）》 2019年 第13卷 第2期   页码 296-306 doi: 10.1007/s11708-018-0605-8

摘要： This paper proposes a powertrain controller for a solar photovoltaic battery powered hybrid electric vehicle (HEV). The main objective of the proposed controller is to ensure better battery management, load regulation, and maximum power extraction whenever possible from the photovoltaic panels. The powertrain controller consists of two levels of controllers named lower level controllers and a high-level control algorithm. The lower level controllers are designed to perform individual tasks such as maximum power point tracking, battery charging, and load regulation. The perturb and observe based maximum power point tracking algorithm is used for extracting maximum power from solar photovoltaic panels while the battery charging controller is designed using a PI controller. A high-level control algorithm is then designed to switch between the lower level controllers based on different operating conditions such as high state of charge, low state of charge, maximum battery current, and heavy load by respecting the constraints formulated. The developed algorithm is evaluated using theoretical simulation and experimental studies. The simulation and experimental results are presented to validate the proposed technique.

关键词： battery management system     hybrid electric vehicles (HEVs)     maximum power point tracking (MPPT)     solar photovoltaic    

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Fatigue shear performance of concrete beams reinforced with hybrid (glass-fiber-reinforced polymer+ steel

《结构与土木工程前沿（英文）》 2021年 第15卷 第3期   页码 576-594 doi: 10.1007/s11709-021-0728-6

摘要： Reinforced concrete beams consisting of both steel and glass-fiber-reinforced polymer rebars exhibit excellent strength, serviceability, and durability. However, the fatigue shear performance of such beams is unclear. Therefore, beams with hybrid longitudinal bars and hybrid stirrups were designed, and fatigue shear tests were performed. For specimens that failed by fatigue shear, all the glass-fiber-reinforced polymer stirrups and some steel stirrups fractured at the critical diagonal crack. For the specimen that failed by the static test after 8 million fatigue cycles, the static capacity after fatigue did not significantly decrease compared with the calculated value. The initial fatigue level has a greater influence on the crack development and fatigue life than the fatigue level in the later phase. The fatigue strength of the glass-fiber-reinforced polymer stirrups in the specimens was considerably lower than that of the axial tension tests on the glass-fiber-reinforced polymer bar in air and beam-hinge tests on the glass-fiber-reinforced polymer bar, and the failure modes were different. Glass-fiber-reinforced polymer stirrups were subjected to fatigue tension and shear, and failed owing to shear.

关键词： fatigue     shear     hybrid stirrups     hybrid reinforcement     fiber-reinforced polymer    

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Breeding strategies for increasing yield potential in super hybrid rice

Shihua CHENG,Xiaodeng ZHAN,Liyong CAO

《农业科学与工程前沿（英文）》 2015年 第2卷 第4期   页码 277-282 doi: 10.15302/J-FASE-2015081

摘要： Super hybrid rice breeding is a new breeding method combining semi-dwarf breeding and heterosis breeding using germplasm and gene-environment interactions. This paper reviews the breeding strategies of super hybrid rice breeding in China, focusing on the utilization of heterosis of indica and japonica subspecies, construction of ideal plant architecture and pyramiding of disease resistant genes in restorer lines. To develop super hybrid rice, considerable effort should be made to explore genes related with high yield, good quality, resistance to pests and diseases, tolerance to stresses. Molecular breeding methods in combination with crossing techniques should be adopted in super hybrid rice breeding.

关键词： super hybrid rice     breeding strategies     yield potential    

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标题 作者 时间 类型 操作

Design of a novel side-mounted leg mechanism with high flexibility for a multi-mission quadruped earth

期刊论文

Operation analysis of a Chebyshev-Pantograph leg mechanism for a single DOF biped robot

Conghui LIANG, Marco CECCARELLI, Yukio TAKEDA

期刊论文

Design method and verification of a hybrid prosthetic mechanism with energy-damper clutchable device

期刊论文

Load-sharing mechanism in timber-steel hybrid shear wall systems

Zheng LI,Minjuan HE,Frank LAM,Minghao LI

期刊论文

Hybrid forming mechanism of patternless casting and laser cladding

Zhongde SHAN, Fuzhen SUN, Yang LIU

期刊论文

Different manipulation mode analysis of a radial symmetrical hexapod robot with leg–arm integration

期刊论文

A feasibility study on the design and walking operation of a biped locomotor via dynamic simulation

null

期刊论文

pyrolysis to convert biomass to versatile 3D carbon nanotubes/mesoporous carbon architecture: conversion mechanism

期刊论文

Performance investigation of artificial intelligence based controller for three phase four leg shunt

J. JAYACHANDRAN,R. MURALI SACHITHANANDAM

期刊论文

Intelligent hybrid power generation system using new hybrid fuzzy-neural for photovoltaic system and

Alireza REZVANI,Ali ESMAEILY,Hasan ETAATI,Mohammad MOHAMMADINODOUSHAN

期刊论文

Robust ensemble of metamodels based on the hybrid error measure

期刊论文

Diffusion process in enzyme–metal hybrid catalysts

期刊论文

Powertrain control of a solar photovoltaic-battery powered hybrid electric vehicle

P. PADMAGIRISAN, V. SANKARANARAYANAN

期刊论文

Fatigue shear performance of concrete beams reinforced with hybrid (glass-fiber-reinforced polymer+ steel

期刊论文

Breeding strategies for increasing yield potential in super hybrid rice

Shihua CHENG,Xiaodeng ZHAN,Liyong CAO

期刊论文