Passive bionic feet,known for their human-like compliance,have garnered attention for their potential to achieve notable environmental adaptability.In this paper,a method was proposed to unifying passive bionic feet s...Passive bionic feet,known for their human-like compliance,have garnered attention for their potential to achieve notable environmental adaptability.In this paper,a method was proposed to unifying passive bionic feet static supporting stability and dynamic terrain adaptability through the utilization of the Rigid-Elastic Hybrid(REH)dynamics model.First,a bionic foot model,named the Hinge Tension Elastic Complex(HTEC)model,was developed by extracting key features from human feet.Furthermore,the kinematics and REH dynamics of the HTEC model were established.Based on the foot dynamics,a nonlinear optimization method for stiffness matching(NOSM)was designed.Finally,the HTEC-based foot was constructed and applied onto BHR-B2 humanoid robot.The foot static stability is achieved.The enhanced adaptability is observed as the robot traverses square steel,lawn,and cobblestone terrains.Through proposed design method and structure,the mobility of the humanoid robot is improved.展开更多
A novel layered method was proposed to solve the problem of Web services composition.In this method,services composition problem was formally transformed into the optimal matching problem of every layer,then optimal m...A novel layered method was proposed to solve the problem of Web services composition.In this method,services composition problem was formally transformed into the optimal matching problem of every layer,then optimal matching problem was modeled based on the hypergraph theory,and solved by computing the minimal transversals of the hypergraph.Meanwhile,two optimization algorithms were designed to discard some useless states at the intermediary steps of the composition algorithm.The effectiveness of the composition method was tested by a set of experiments,in addition,an example regarding the travel services composition was also given.The experimental results show that this method not only can automatically generate composition tree whose leaf nodes correspond to services composition solutions,but also has better performance on execution time and solution quality by adopting two proposed optimization algorithms.展开更多
The relationship between engine mechanics and thermo-dynamics has been investigated by means of numerical simulation.The inherent mismatching between the mechanical behaviors and the thermodynamic process in internal ...The relationship between engine mechanics and thermo-dynamics has been investigated by means of numerical simulation.The inherent mismatching between the mechanical behaviors and the thermodynamic process in internal combustion engine is identified,which is believed to be one of the important limiting factors of energy efficiency for conventional engines available in the current market.An approach for engine efficiency improvement through optimal matching between mechanics and thermodynamics(OMBMT)is proposed.An ideal matching model is defined and the conflicts due to the constraints among the mapping strokes in a 4-stroke engine are analyzed.A novel mechanical model is built for approaching optimal matching among all 4 individual strokes in a 4-stroke spark-ignition engine,which is composed of non-circular gears(NCG)and integrated with conventional slider crank engine mechanism.By means of digital mechanical model and numerical simulation,the matching gains among all 4 strokes are defined and calculated for quantifying the NCG engine efficiency improvement by comparing with a baseline engine.The potentials with the OMBMT implemented and the enhancements made by NCG mechanism for engines in terms of overall engine efficiency are reported.Based on the results achieved,it is recommended that the feasibility studies and the experimental validations should be conducted to verify the engine matching concept and effectiveness of the NCG mechanism engine model proposed,and the engine performance and NCG design parameters should be further optimized.展开更多
Based on the comprehensive comparison of vehicle performance in economy,engine power,driving smoothness,and efficiency cost as well as pollutant emission etc,the paper discussed the high value CVT concept from an angl...Based on the comprehensive comparison of vehicle performance in economy,engine power,driving smoothness,and efficiency cost as well as pollutant emission etc,the paper discussed the high value CVT concept from an angle of the cost effective and powerful for vehicle.In the paper,it researched the related technical detail in CVT.By means of realizing the continuous change in transmission ratio,it could obtain the optimal matching between transmission system and engine operating mode,and enhance the characteristic of fuel oil in economy,and also improve the convenience in manipulation for driver and make passenger comfortable.For easy to understand the concept,the paper made the comparison analysis in many aspects such as performance,transmission specification,high value CVT hybrid,orifice torque sensor,hydraulic system,high value CVT em,new chain portfolio and assessment of the high value CVT on the NEDC.Finally it showed the potential advantages of CVT technology development,and proposed future developing trends to realize technical scheme of high value CVT.展开更多
Red,blue and green visible lasers are more attractive with the development of the science and technology.Self frequency doubling is an important approach to realize visible lasers.For self frequency doubling,the basic...Red,blue and green visible lasers are more attractive with the development of the science and technology.Self frequency doubling is an important approach to realize visible lasers.For self frequency doubling,the basic requests are high figure of merit(FOM),high damage threshold,good chemical stability and mechanical properties.Perfection and growth characters are also important for a practical SFD crystal. In recent years,the discovery of rare earth calcium oxyborates has resulted in the renewal in the field of SFD crystal.ReCaO(BO 3) 3(ReCOB)is a new type of novel nonlinear optical crystals which is nearly congruently melt and can be grown with Czochralski method.ReCOB crystals possess high nonlinear coefficients and damage thresholds.They are non hydroscopic and easy cutting and polishing.They belong to monoclinic with point group m and space group cm.The strong anisotropy originated from the low symmetry makes the measurement and application of the crystal more complicated.More than half of naturally existed crystals belongs to low symmetry,consequently,the research on the nonlinear and anisotropic laser optical properties are not only important for ReCOB crystal,but also useful for the applications of other low symmetry crystals.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.62073041)the Open Fund of Laboratory of Aerospace Servo Actuation and Transmission(Grant No.LASAT-2023A04)the Fundamental Research Funds for the Central Universities(Grant Nos.2024CX06011,2024CX06079)。
文摘Passive bionic feet,known for their human-like compliance,have garnered attention for their potential to achieve notable environmental adaptability.In this paper,a method was proposed to unifying passive bionic feet static supporting stability and dynamic terrain adaptability through the utilization of the Rigid-Elastic Hybrid(REH)dynamics model.First,a bionic foot model,named the Hinge Tension Elastic Complex(HTEC)model,was developed by extracting key features from human feet.Furthermore,the kinematics and REH dynamics of the HTEC model were established.Based on the foot dynamics,a nonlinear optimization method for stiffness matching(NOSM)was designed.Finally,the HTEC-based foot was constructed and applied onto BHR-B2 humanoid robot.The foot static stability is achieved.The enhanced adaptability is observed as the robot traverses square steel,lawn,and cobblestone terrains.Through proposed design method and structure,the mobility of the humanoid robot is improved.
基金Project(2010CB328101) supported by the National Basic Research Program of ChinaProject(2009AA01Z401) supported by the National High Technology Research and Development Program of China+4 种基金Projects(60803032,90818023) supported by the National Natural Science Foundation of ChinaProjects(09510701300,09JC1414200,09DZ1120403) supported by the Shanghai Science and Technology Commission,China"Shu Guang" Project(10SG23) supported by Shanghai Municipal Education Commission and Shanghai Education Development Foundation,ChinaProject(09QA1405800) supported by Shanghai Science and Technology Commission Rising-Star Program,ChinaProject(NCET-10-0598) supported by Program for New Century Excellent Talents in Chinese University
文摘A novel layered method was proposed to solve the problem of Web services composition.In this method,services composition problem was formally transformed into the optimal matching problem of every layer,then optimal matching problem was modeled based on the hypergraph theory,and solved by computing the minimal transversals of the hypergraph.Meanwhile,two optimization algorithms were designed to discard some useless states at the intermediary steps of the composition algorithm.The effectiveness of the composition method was tested by a set of experiments,in addition,an example regarding the travel services composition was also given.The experimental results show that this method not only can automatically generate composition tree whose leaf nodes correspond to services composition solutions,but also has better performance on execution time and solution quality by adopting two proposed optimization algorithms.
文摘The relationship between engine mechanics and thermo-dynamics has been investigated by means of numerical simulation.The inherent mismatching between the mechanical behaviors and the thermodynamic process in internal combustion engine is identified,which is believed to be one of the important limiting factors of energy efficiency for conventional engines available in the current market.An approach for engine efficiency improvement through optimal matching between mechanics and thermodynamics(OMBMT)is proposed.An ideal matching model is defined and the conflicts due to the constraints among the mapping strokes in a 4-stroke engine are analyzed.A novel mechanical model is built for approaching optimal matching among all 4 individual strokes in a 4-stroke spark-ignition engine,which is composed of non-circular gears(NCG)and integrated with conventional slider crank engine mechanism.By means of digital mechanical model and numerical simulation,the matching gains among all 4 strokes are defined and calculated for quantifying the NCG engine efficiency improvement by comparing with a baseline engine.The potentials with the OMBMT implemented and the enhancements made by NCG mechanism for engines in terms of overall engine efficiency are reported.Based on the results achieved,it is recommended that the feasibility studies and the experimental validations should be conducted to verify the engine matching concept and effectiveness of the NCG mechanism engine model proposed,and the engine performance and NCG design parameters should be further optimized.
文摘Based on the comprehensive comparison of vehicle performance in economy,engine power,driving smoothness,and efficiency cost as well as pollutant emission etc,the paper discussed the high value CVT concept from an angle of the cost effective and powerful for vehicle.In the paper,it researched the related technical detail in CVT.By means of realizing the continuous change in transmission ratio,it could obtain the optimal matching between transmission system and engine operating mode,and enhance the characteristic of fuel oil in economy,and also improve the convenience in manipulation for driver and make passenger comfortable.For easy to understand the concept,the paper made the comparison analysis in many aspects such as performance,transmission specification,high value CVT hybrid,orifice torque sensor,hydraulic system,high value CVT em,new chain portfolio and assessment of the high value CVT on the NEDC.Finally it showed the potential advantages of CVT technology development,and proposed future developing trends to realize technical scheme of high value CVT.
文摘Red,blue and green visible lasers are more attractive with the development of the science and technology.Self frequency doubling is an important approach to realize visible lasers.For self frequency doubling,the basic requests are high figure of merit(FOM),high damage threshold,good chemical stability and mechanical properties.Perfection and growth characters are also important for a practical SFD crystal. In recent years,the discovery of rare earth calcium oxyborates has resulted in the renewal in the field of SFD crystal.ReCaO(BO 3) 3(ReCOB)is a new type of novel nonlinear optical crystals which is nearly congruently melt and can be grown with Czochralski method.ReCOB crystals possess high nonlinear coefficients and damage thresholds.They are non hydroscopic and easy cutting and polishing.They belong to monoclinic with point group m and space group cm.The strong anisotropy originated from the low symmetry makes the measurement and application of the crystal more complicated.More than half of naturally existed crystals belongs to low symmetry,consequently,the research on the nonlinear and anisotropic laser optical properties are not only important for ReCOB crystal,but also useful for the applications of other low symmetry crystals.
