Against the backdrop of active global responses to climate change and the accelerated green and low-carbon energy transition,the co-optimization and innovative mechanism design of multimodal energy systems have become...Against the backdrop of active global responses to climate change and the accelerated green and low-carbon energy transition,the co-optimization and innovative mechanism design of multimodal energy systems have become a significant instrument for propelling the energy revolution and ensuring energy security.Under increasingly stringent carbon emission constraints,how to achieve multi-dimensional improvements in energy utilization efficiency,renewable energy accommodation levels,and system economics-through the intelligent coupling of diverse energy carriers such as electricity,heat,natural gas,and hydrogen,and the effective application of market-based instruments like carbon trading and demand response-constitutes a critical scientific and engineering challenge demanding urgent solutions.展开更多
Aiming at the innovative design requirements of rehabilitation robots with multiple kinematically coupled components and the current absence of systematic processes in the design of such mechanisms,this paper presents...Aiming at the innovative design requirements of rehabilitation robots with multiple kinematically coupled components and the current absence of systematic processes in the design of such mechanisms,this paper presents the concept of a multi-output component mechanism(MOCM).A classification methodology for the MOCM is proposed based on the operational coupling between the actuators and the output components within closedloop mechanisms.Building on the classification results,a design methodology for a kinematically coupled MOCM(KCMOCM)is proposed based on the actuation distribution within the closed-loop sub-mechanisms.First,the number and relative kinematic characteristics of the output components are determined based on the application environment of the mechanism.These components are then grouped and classified according to motion similarity principles,followed by the design of closed-loop sub-mechanisms with actuators for each group,ultimately forming a complete KCMOCM.Taking the sit-stand-lie-bed mechanism in a spinal cord injury lower-limb rehabilitation robot as an example,this study comprehensively considers the multi-posture transition task requirements and spatial constraint characteristics of lower-limb rehabilitation training to design the mechanism.By applying the mechanism design methodology,six practical novel configurations are developed with established evaluation criteria,and kinematic analysis and experimental validation are performed on the optimized configuration.The results demonstrate that the optimized configuration satisfies the multi-posture rehabilitation training requirements for lower limbs.This validates the efficacy of the design methodology.Furthermore,the scalability of the design methodology is validated through the development of a robotic finger rehabilitation mechanism.展开更多
A new spherical mobile robot BHQ-1 is designed. The spherical robot is driven by two internally mounted motors that induce the ball to move straight and turn around on a fiat surface. A dynamic model of the robot is d...A new spherical mobile robot BHQ-1 is designed. The spherical robot is driven by two internally mounted motors that induce the ball to move straight and turn around on a fiat surface. A dynamic model of the robot is developed with Lagrange method and factors affecting the driving torque of two motors are analyzed. The relationship between the turning radius of the robot and the length of two links is discussed in order to optimize its mechanism design. Simulation and experimental results demonstrate the good controllability and motion performance of BHQ-1.展开更多
Trailing-edge flap is traditionally used to improve the takeoff and landing aerodynamic performance of aircraft.In order to improve flight efficiency during takeoff,cruise and landing states,the flexible variable camb...Trailing-edge flap is traditionally used to improve the takeoff and landing aerodynamic performance of aircraft.In order to improve flight efficiency during takeoff,cruise and landing states,the flexible variable camber trailing-edge flap is introduced,capable of changing its shape smoothly from 50% flap chord to the rear of the flap.Using a numerical simulation method for the case of the GA（W）-2 airfoil,the multi-objective optimization of the overlap,gap,deflection angle,and bending angle of the flap under takeoff and landing configurations is studied.The optimization results show that under takeoff configuration,the variable camber trailing-edge flap can increase lift coefficient by about 8% and lift-to-drag ratio by about 7% compared with the traditional flap at a takeoff angle of 8°.Under landing configuration,the flap can improve the lift coefficient at a stall angle of attack about 1.3%.Under cruise state,the flap helps to improve the lift-todrag ratio over a wide range of lift coefficients,and the maximum increment is about 30%.Finally,a corrugated structure–eccentric beam combination bending mechanism is introduced in this paper to bend the flap by rotating the eccentric beam.展开更多
Heavy-load transfer robots are widely used in automobile production and machinery manufacturing to improve production efficiency.In order to meet the needs of large billet transfer,a 4-DOF transfer robot is designed i...Heavy-load transfer robots are widely used in automobile production and machinery manufacturing to improve production efficiency.In order to meet the needs of large billet transfer,a 4-DOF transfer robot is designed in this paper,which consists of parallel four-bar mechanisms.The Jacobian matrix referring to the mapping matrix from the joint velocity to the operating space velocity of the transfer robot can be solved by the differential-vector method.The mean value of the Jacobian matrix condition number in the workspace is used as the global performance index of the robot velocity and the optimization goal.The constraint condition is established based on the actual working condition.Then the linkage length optimization is carried out to decrease the length of the linkage and to increase the global performance index of velocity.The total length of robot rods is reduced by 6.12%.The global performance index of velocity is improved by 45.15%.Taking the optimized rod length as the mechanism parameter,the distribution of the motion space of the transfer robot is obtained.Finally,the results show that the proposed method for establishing the Jacobian matrix of the lower-mobility robot and for the optimization of the rods based on the velocity global performance index is accurate and effective.The workspace distribution of the robot meets the design requirements.展开更多
In recent years, the researches on the theory and application of public articles and mechanism design at home and abroad has attracted more and more attentions. The paper uses the idea of mechanism design and simulati...In recent years, the researches on the theory and application of public articles and mechanism design at home and abroad has attracted more and more attentions. The paper uses the idea of mechanism design and simulation to analyze and solve environmental pollution improvement. By establishing a simple environmental pollution improvement model, the paper transforms pollution control into binary decision established by a sewage treatment plant and different decisions by the fisherman on the establishment of sewage treatment plants. The paper observes the results of applying different mechanisms and proposes the suggestions of implementin~ various pollution control methods.展开更多
The double-chain space manipulator(DCSM)can complete collaborative tasks in a large workspace,which is of great significance for its development.The complex structure and multiple variables of the DCSM present signifi...The double-chain space manipulator(DCSM)can complete collaborative tasks in a large workspace,which is of great significance for its development.The complex structure and multiple variables of the DCSM present significant challenges for DCSM design.In this paper,an integrated type and dimension method for DCSM design of using a Q-learning-based mixed-integer optimization method was proposed.Based on the analysis of the mechanism characteristics of the DCSM,a model-free kinematics modeling method was proposed for unknown configurations,and the discrete variables,including the number and axis direction of joints,and the continuous variables,including the link lengths,were linearized,enabling the subsequent efficient optimization.Then,a performance index system,including workspace,comprehensive operability and follow-up sensitivity,was established,which reflects the coupling relationship between the main chain and the branch chains with regard to performance.By introducing the ideas of judgment and decision-making from Q-learning into the mechanism design,efficient optimization of multiple variables under complex performance constraints was achieved.The analysis results indicate that the method proposed in this paper has high convergence speed and computational efficiency,and can obtain multiple feasible solutions of different types.This study provides the basis for the design of manipulators with complex configurations and multiple variables.展开更多
Based on a level set model, a topology optimization method has been suggestedrecently. It uses a level set to express the moving structural boundary, which can flexibly handlecomplex topological changes. By combining ...Based on a level set model, a topology optimization method has been suggestedrecently. It uses a level set to express the moving structural boundary, which can flexibly handlecomplex topological changes. By combining vector level set models with gradient projectiontechnology, the level set method for topological optimization is extended to a topologicaloptimization problem with multi-constraints, multi-materials and multi-load cases. Meanwhile, anappropriate nonlinear speed, mapping is established in the tangential space of the activeconstraints for a fast convergence. Then the method is applied to structure designs, mechanism andmaterial designs by a number of benchmark examples. Finally, in order to further improvecomputational efficiency and overcome the difficulty that the level set method cannot generate newmaterial interfaces during the optimization process, the topological derivative analysis isincorporated into the level set method for topological optimization, and a topological derivativeand level set algorithm for topological optimization is proposed.展开更多
Increasing penetration of distributed energy resources in the distribution network(DN)is threatening safe operation of the DN,which necessitates setup of the ancillary service market in the DN.In the ancillary service...Increasing penetration of distributed energy resources in the distribution network(DN)is threatening safe operation of the DN,which necessitates setup of the ancillary service market in the DN.In the ancillary service market,distribution system operator(DSO)is responsible for safety of the DN by procuring available capacities of aggregators.Unlike existing studies,this paper proposes a novel market mechanism composed of two parts:choice rule and payment rule.The proposed choice rule simultaneously considers social welfare and fairness,encouraging risk-averse aggregators to participate in the ancillary service market.It is then formulated as a linear programming problem,and a distributed solution using the multi-cut Benders decomposition is presented.Moreover,successful implementation of the choice rule depends on each aggregator’s truthful adoption of private parameters.Therefore,a payment rule is also designed,which is proved to possess two properties:incentive compatibility and individual rationality.Simulation results demonstrate effectiveness of the proposed choice rule on improving fairness and verify properties of the payment rule.展开更多
Reverse auctions of PPP projects usually require the bid to specify several characteristics of quality and the concession period to be fulfilled. This paper sets up a summary function of generalized quality, which con...Reverse auctions of PPP projects usually require the bid to specify several characteristics of quality and the concession period to be fulfilled. This paper sets up a summary function of generalized quality, which contributes to reducing the dimensions of information.Thus, the multidimensional reverse auction model of a PPP project can be replaced by a two-dimensional direct mechanism based on the concession period and the generalized quality. Based on the theory of the revelation principle, the feasibility conditions, equilibrium solution and generalized quality requirements of such a mechanism,considering the influence of a variable investment structure are described. Moreover, two feasible multidimensional reverse auctions for implementing such a direct mechanism: Adjusting the scoring function and establishing a special reverse auction rule are built. The analysis shows that in these types of reverse auctions, optimal allocation can be achieved, the social benefit under the incomplete information will be maximized, and the private sector with the highest integrated management level wins the bid. In such a direct mechanism, the investment and financial pressure of the public sector can be reduced.展开更多
Animals can adapt to their surroundings by modifying their trunk morphology,whereas legged robots currently utilize rigid trunks.This study introduces a single-degree-of-freedom(DoF),six-revolute(6R)morphing trunk mec...Animals can adapt to their surroundings by modifying their trunk morphology,whereas legged robots currently utilize rigid trunks.This study introduces a single-degree-of-freedom(DoF),six-revolute(6R)morphing trunk mechanism designed to equip legged robots with variable-width capabilities.Subsequently,a morphology-aware locomotion learning pipeline,based on reinforcement learning,is proposed for real-time trunk-width deformation and adaptive legged locomotion.The proposed variable-width trunk is integrated into a quadrupedal robot,and the learning pipeline is employed to train the adaptive locomotion controller of this robot.This study has three key contributions:(1)An overconstrained morphing mechanism is designed to achieve single-DoF trunk-width deformation,thereby minimizing power consumption and simplifying motion control.(2)A novel morphology-adaptive learning pipeline is introduced that utilizes adversarial joint-level motion imitation to ensure coordination consistency during morphological adaptation.This method addresses dynamic disturbances and interlimb coordination disruptions caused by width modifications.(3)A historical proprioception-based asymmetric neural network architecture is utilized to attain implicit terrain perception without visual input.Collectively,these developments enable the proposed variable-width legged robot to maintain consistent locomotion across complex terrains and facilitate rapid width deformation in response to environmental changes.Extensive simulation experiments validate the proposed design and control methodology.展开更多
The optimization of metamorphic mechanisms is different from that of the conventional mechanisms for its characteristics of multi-configuration. There exist complex coupled design variables and constraints in its mult...The optimization of metamorphic mechanisms is different from that of the conventional mechanisms for its characteristics of multi-configuration. There exist complex coupled design variables and constraints in its multiple different configuration optimization models. To achieve the compatible optimized results of these coupled design variables, an optimization method for metamorphic mechanisms is developed in the paper based on the principle of multidisciplinary design optimization（MDO）. Firstly, the optimization characteristics of the metamorphic mechanism are summarized distinctly by proposing the classification of design variables and constraints as well as coupling interactions among its different configuration optimization models. Further, collaborative optimization technique which is used in MDO is adopted for achieving the overall optimization performance. The whole optimization process is then proposed by constructing a two-level hierarchical scheme with global optimizer and configuration optimizer loops. The method is demonstrated by optimizing a planar five-bar metamorphic mechanism which has two configurations,and results show that it can achieve coordinated optimization results for the same parameters in different configuration optimization models.展开更多
Non-renewable fossil fuels have led to serious problems such as global warming,environmental pollution,etc.Oxygen electrocatalysis including oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)plays a cent...Non-renewable fossil fuels have led to serious problems such as global warming,environmental pollution,etc.Oxygen electrocatalysis including oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)plays a central role in clean energy conversion,enabling a number of sustainable processes for future air battery technologies.Fluorine,as the most electronegative element(4.0)not only can induce more efficient regulation for the electronic structure,but also can bring more abundant defects and other novel effects in materials selection and preparation for favorable catalysis with respect to the other nonmetal elements.However,an individual and comprehensive overview of fluorine-containing functional materials for oxygen electrocatalysis field is still blank.Therefore,it is very meaningful to review the recent progresses of fluorine-containing oxygen electrocatalysts.In this review,we first systematically summarize the controllable preparation methods and their possible development directions based on fluorine-containing materials from four preparation methods.Due to the strong electron-withdrawing properties of fluorine,its control of the electronic structure can effectively enhance the oxygen electrocatalytic activity of the materials.In addition,the catalytic enhancement effect of fluorine on carbonbased materials also includes the prevent oxidation and the layer peeling,and realizes the precise atomic control.And the catalytic improvement mechanism of fluorine containing metal-based compounds also includes the hydration of metal site,the crystal transformation,and the oxygen vacancy induction.Then,based on their various dimensions(0D–3D),we also have summarized the advantages of different morphologies on oxygen electrocatalytic performances.Finally,the prospects and possible future researching direction of F-containing oxygen electrocatalysts are presented(e.g.,novel pathways,advanced methods for measurement and simulation,field assistance and multi-functions).The review is considered valuable and helpful in exploring the novel designs and mechanism analyses of advanced fluorine-containing electrocatalysts.展开更多
We first design and analyze the contour surface of the globoidal indexing cam with the aid of computer, and then do optimum design according to the requirements of dynamics. Finally, we discuss the problem of the pres...We first design and analyze the contour surface of the globoidal indexing cam with the aid of computer, and then do optimum design according to the requirements of dynamics. Finally, we discuss the problem of the pressure angle of the globoidal indexing cam mechanism in detail and put forward a new concept of equivalent pressure angle.展开更多
Icing as a regular natural phenomenon in life poses a serious threat to human production and life,traditional mechanical deicing,chemical deicing,and other methods have the shortcomings of high pollution,high energy c...Icing as a regular natural phenomenon in life poses a serious threat to human production and life,traditional mechanical deicing,chemical deicing,and other methods have the shortcomings of high pollution,high energy consumption,and low efficiency,which limits their applicability and effectiveness of the scene of the above methods.With the expansion of global economic activities in recent years,the solution to the icing problem has become imminent.As a result,researchers have gradually deepened their studies related to anti-icing.Inspired by the lotus leaf effect,hogwash,polar,marine shellfish,and other natural organisms,anti-icing/deicing coatings can be designed functional biomimetic through both surface micro-nano structures and the physicochemical properties of the material.Superhydrophobic design is based on Young’s wetting equations,Wenzel’s wetting equations,and the Cassie-Baxter model of the superhydrophobic behavior of the interface formed by the liquid droplets and the surface,which prevents the droplets from spreading out and penetration to form heat exchange.The physicochemical properties are based on the slow-release behavior of chemical mediators inside the coating with properties such as super-lubrication and anti-freezing,which reduce the residence time and nucleation temperature of droplets on the surface.The coating effectively blocks the occurrence of icing behavior by passive means such as ultra-low interfacial wetting,interfacial slip,and lowering the freezing point of droplets,which has become a hot research direction.Meanwhile,the active anti-icing of photo-thermal,electro-thermal,phase change and other effects with the passive anti-icing to play a synergistic and complementary role for further enhance the anti-icing effect of the coating.To clarity the design mechanism and preparation process of the anti-icing/ice-removing surfaces,the article firstly classifies and introduces the coatings functioned according to the different mechanisms of action,and sums up the biomimetic super-hydrophobic design,the sacrificial type physicochemical characteristic.The article firstly classifies and introduces the functional types of coatings according to different mechanisms of action,and the latest research progress on the mechanism design of anti-icing coatings and their performance modification such as bionic superhydrophobic design,sacrificial physicochemical property design,microregion modulus control design and multifactorial coupling design were summarized.The problems of single-functionality and imbalance of performance of the existing coating mechanism design were analyzed and discussed,the view of the development trend and outlook of the development and application of icephobic coatings were put forward.展开更多
Solid–liquid separation is widely used in daily life and practical engineering.Traditional industrial filters are prone to clogging,but this rarely occurs in filter-feeding organisms.Inspired by the filter feeding me...Solid–liquid separation is widely used in daily life and practical engineering.Traditional industrial filters are prone to clogging,but this rarely occurs in filter-feeding organisms.Inspired by the filter feeding mechanism of balaenid whales and considering the local grooves in the fringes layer,a new bionic filter is produced by 3D printing technology through the bionic design of the parallel channels inside the mouth of balaenid whales.At the same time,a test platform composed of the bionic filter,peristaltic pump,fluid pulse rectifier and water tank is built to carry out the fluid flow pattern dyeing and particle filtration experiments.It is found that fluid separation occurs near the groove structure and local vortices are generated.The vortex control filtration mechanism makes the particles in the front grooves tend to accumulate on the left side,which has a certain anti-clogging effect.Moreover,the increase of flow velocity leads to the enhancement of vortices,which makes the accumulation effect on the left more obvious.This study initially practices the bionic application from biological model to engineering design,and the vortex control anti-clogging filtration mechanism proposed in the study has a wide range of application prospects and values.展开更多
Radio frequency(RF)cavities for advanced storage rings,also known as diffraction-limited storage rings,are under development.To this end,a competitive and promising approach involves normal-conducting continuous wave ...Radio frequency(RF)cavities for advanced storage rings,also known as diffraction-limited storage rings,are under development.To this end,a competitive and promising approach involves normal-conducting continuous wave technology.The design and preliminary test of a 499.654 MHz RF cavity for the Wuhan Advanced Light Source(WALS)based on specific beam parameters were conducted at the SSRF.Multi-objective evolutionary algorithms have been utilized to optimize RF properties,such as the power loss and power density,resulting in better performance in the continuous wave mode.Further improvements were made to suppress multipacting effects in the working area.To operate stably with the beam,higher-order mode dampers were applied to better address the coupling bunch instability than in previous designs,along with thermal analysis to achieve the desired RF performance.Comprehensive simulation studies demonstrated the stable operation of the RF cavity at the defined beam parameters in the WALS design.A prototype RF cavity was then developed,and the RF performance results in a low-power test showed good agreement with the design and simulation,exhibiting readiness for high-power experiments and operation.展开更多
Materials mechanics and structural dynamics provide theoretical support for the structural optimization of amusement facilities.The design code system guides the design process,covering aspects such as strength and fa...Materials mechanics and structural dynamics provide theoretical support for the structural optimization of amusement facilities.The design code system guides the design process,covering aspects such as strength and fatigue life.This paper introduces optimization methods like standardized module interfaces and variable density methods,as well as topics related to finite element simulation,reliability enhancement,innovative practices,and their significance.展开更多
As a product of the new century,artificial intelligence has been continuously developed and advanced.It has been applied to many fields,especially in the field of mechanical design and manufacturing.With the support o...As a product of the new century,artificial intelligence has been continuously developed and advanced.It has been applied to many fields,especially in the field of mechanical design and manufacturing.With the support of artificial intelligence,mechanical design and manufacturing can not only reduce input costs but also significantly reduce the demand for labor,playing a positive role in improving the design efficiency and quality of mechanical manufacturing[1].This paper studies how to apply artificial intelligence technology to the mechanical design and production process to achieve greater application and development.展开更多
With the acceleration of the global aging process and the increase of cardiovascular ancerebrovascular diseases,more and more patients are paralyzed due to accidents,so theexoskeleton robot began to appear in people&#...With the acceleration of the global aging process and the increase of cardiovascular ancerebrovascular diseases,more and more patients are paralyzed due to accidents,so theexoskeleton robot began to appear in people's sight,and the lower limb exoskeleton robot withrehabilitation training is also favored by more and more people.In this paper,the structural designand analysis of the lower limb exoskeleton robot are carried out in view of the patients'expectation ofnormal walking.First,gait analysis and structural design of lower limb exoskeleton robot.Based onthe analysis of the walking gait of normal people,the freedom of the three key joints of the lower limbexoskeleton robot hip joint,knee joint and ankle joint is determined.at the same time,according tothe structuralcharacteristics of each joint,the three key joints are modeled respectively,and theoverall model assembly of the lower limb exoskeleton robot is completed.Secondly,the kinematicsanalysis of the lower limb exoskeleton robot was carried out to obtain the relationship between thelinear displacement,linear speed and acceleration of each joint,so as to ensure the coordination ofthe model with the human lower limb movement.Thirdly,the static analysis of typical gait of hipjoint,knee joint and ankle joint is carried out to verify the safety of the design model under thepremise of ensuring the structural strength requirements.Finally,the parts of the model were 3Dprinted,and the rationality of the design was further verified in the process of assembling the model.展开更多
文摘Against the backdrop of active global responses to climate change and the accelerated green and low-carbon energy transition,the co-optimization and innovative mechanism design of multimodal energy systems have become a significant instrument for propelling the energy revolution and ensuring energy security.Under increasingly stringent carbon emission constraints,how to achieve multi-dimensional improvements in energy utilization efficiency,renewable energy accommodation levels,and system economics-through the intelligent coupling of diverse energy carriers such as electricity,heat,natural gas,and hydrogen,and the effective application of market-based instruments like carbon trading and demand response-constitutes a critical scientific and engineering challenge demanding urgent solutions.
基金Supported by National Key Research and Development Program of China(Grant No.2019YFB1312500)。
文摘Aiming at the innovative design requirements of rehabilitation robots with multiple kinematically coupled components and the current absence of systematic processes in the design of such mechanisms,this paper presents the concept of a multi-output component mechanism(MOCM).A classification methodology for the MOCM is proposed based on the operational coupling between the actuators and the output components within closedloop mechanisms.Building on the classification results,a design methodology for a kinematically coupled MOCM(KCMOCM)is proposed based on the actuation distribution within the closed-loop sub-mechanisms.First,the number and relative kinematic characteristics of the output components are determined based on the application environment of the mechanism.These components are then grouped and classified according to motion similarity principles,followed by the design of closed-loop sub-mechanisms with actuators for each group,ultimately forming a complete KCMOCM.Taking the sit-stand-lie-bed mechanism in a spinal cord injury lower-limb rehabilitation robot as an example,this study comprehensively considers the multi-posture transition task requirements and spatial constraint characteristics of lower-limb rehabilitation training to design the mechanism.By applying the mechanism design methodology,six practical novel configurations are developed with established evaluation criteria,and kinematic analysis and experimental validation are performed on the optimized configuration.The results demonstrate that the optimized configuration satisfies the multi-posture rehabilitation training requirements for lower limbs.This validates the efficacy of the design methodology.Furthermore,the scalability of the design methodology is validated through the development of a robotic finger rehabilitation mechanism.
基金This project is supported by National Hi-tech Research and Development Program of China(863 Program, No.2003AA404190).
文摘A new spherical mobile robot BHQ-1 is designed. The spherical robot is driven by two internally mounted motors that induce the ball to move straight and turn around on a fiat surface. A dynamic model of the robot is developed with Lagrange method and factors affecting the driving torque of two motors are analyzed. The relationship between the turning radius of the robot and the length of two links is discussed in order to optimize its mechanism design. Simulation and experimental results demonstrate the good controllability and motion performance of BHQ-1.
文摘Trailing-edge flap is traditionally used to improve the takeoff and landing aerodynamic performance of aircraft.In order to improve flight efficiency during takeoff,cruise and landing states,the flexible variable camber trailing-edge flap is introduced,capable of changing its shape smoothly from 50% flap chord to the rear of the flap.Using a numerical simulation method for the case of the GA（W）-2 airfoil,the multi-objective optimization of the overlap,gap,deflection angle,and bending angle of the flap under takeoff and landing configurations is studied.The optimization results show that under takeoff configuration,the variable camber trailing-edge flap can increase lift coefficient by about 8% and lift-to-drag ratio by about 7% compared with the traditional flap at a takeoff angle of 8°.Under landing configuration,the flap can improve the lift coefficient at a stall angle of attack about 1.3%.Under cruise state,the flap helps to improve the lift-todrag ratio over a wide range of lift coefficients,and the maximum increment is about 30%.Finally,a corrugated structure–eccentric beam combination bending mechanism is introduced in this paper to bend the flap by rotating the eccentric beam.
基金supported by the National Key R&D Program of China(No.2018YFB1307900)the Natural Science Foundation of Shanxi Province(Nos.201901D211009,201901D211010)the Technology In⁃novation Foundation of Shanxi University(No.2019L 0177).
文摘Heavy-load transfer robots are widely used in automobile production and machinery manufacturing to improve production efficiency.In order to meet the needs of large billet transfer,a 4-DOF transfer robot is designed in this paper,which consists of parallel four-bar mechanisms.The Jacobian matrix referring to the mapping matrix from the joint velocity to the operating space velocity of the transfer robot can be solved by the differential-vector method.The mean value of the Jacobian matrix condition number in the workspace is used as the global performance index of the robot velocity and the optimization goal.The constraint condition is established based on the actual working condition.Then the linkage length optimization is carried out to decrease the length of the linkage and to increase the global performance index of velocity.The total length of robot rods is reduced by 6.12%.The global performance index of velocity is improved by 45.15%.Taking the optimized rod length as the mechanism parameter,the distribution of the motion space of the transfer robot is obtained.Finally,the results show that the proposed method for establishing the Jacobian matrix of the lower-mobility robot and for the optimization of the rods based on the velocity global performance index is accurate and effective.The workspace distribution of the robot meets the design requirements.
文摘In recent years, the researches on the theory and application of public articles and mechanism design at home and abroad has attracted more and more attentions. The paper uses the idea of mechanism design and simulation to analyze and solve environmental pollution improvement. By establishing a simple environmental pollution improvement model, the paper transforms pollution control into binary decision established by a sewage treatment plant and different decisions by the fisherman on the establishment of sewage treatment plants. The paper observes the results of applying different mechanisms and proposes the suggestions of implementin~ various pollution control methods.
基金supported by the Beijing Municipal Natural Science Foundation for Distinguished Young Scholars(Grant No.JQ22007)the National Natural Science Foundation of China(Grant No.52275001)。
文摘The double-chain space manipulator(DCSM)can complete collaborative tasks in a large workspace,which is of great significance for its development.The complex structure and multiple variables of the DCSM present significant challenges for DCSM design.In this paper,an integrated type and dimension method for DCSM design of using a Q-learning-based mixed-integer optimization method was proposed.Based on the analysis of the mechanism characteristics of the DCSM,a model-free kinematics modeling method was proposed for unknown configurations,and the discrete variables,including the number and axis direction of joints,and the continuous variables,including the link lengths,were linearized,enabling the subsequent efficient optimization.Then,a performance index system,including workspace,comprehensive operability and follow-up sensitivity,was established,which reflects the coupling relationship between the main chain and the branch chains with regard to performance.By introducing the ideas of judgment and decision-making from Q-learning into the mechanism design,efficient optimization of multiple variables under complex performance constraints was achieved.The analysis results indicate that the method proposed in this paper has high convergence speed and computational efficiency,and can obtain multiple feasible solutions of different types.This study provides the basis for the design of manipulators with complex configurations and multiple variables.
基金This project is supported by National Natural Science Foundation of China(No.598005001, No.10332010) and Key Science and Technology Research Project of Ministry of Education (No.104060).
文摘Based on a level set model, a topology optimization method has been suggestedrecently. It uses a level set to express the moving structural boundary, which can flexibly handlecomplex topological changes. By combining vector level set models with gradient projectiontechnology, the level set method for topological optimization is extended to a topologicaloptimization problem with multi-constraints, multi-materials and multi-load cases. Meanwhile, anappropriate nonlinear speed, mapping is established in the tangential space of the activeconstraints for a fast convergence. Then the method is applied to structure designs, mechanism andmaterial designs by a number of benchmark examples. Finally, in order to further improvecomputational efficiency and overcome the difficulty that the level set method cannot generate newmaterial interfaces during the optimization process, the topological derivative analysis isincorporated into the level set method for topological optimization, and a topological derivativeand level set algorithm for topological optimization is proposed.
基金supported by the National Natural Science Foundation of China(No.52177077).
文摘Increasing penetration of distributed energy resources in the distribution network(DN)is threatening safe operation of the DN,which necessitates setup of the ancillary service market in the DN.In the ancillary service market,distribution system operator(DSO)is responsible for safety of the DN by procuring available capacities of aggregators.Unlike existing studies,this paper proposes a novel market mechanism composed of two parts:choice rule and payment rule.The proposed choice rule simultaneously considers social welfare and fairness,encouraging risk-averse aggregators to participate in the ancillary service market.It is then formulated as a linear programming problem,and a distributed solution using the multi-cut Benders decomposition is presented.Moreover,successful implementation of the choice rule depends on each aggregator’s truthful adoption of private parameters.Therefore,a payment rule is also designed,which is proved to possess two properties:incentive compatibility and individual rationality.Simulation results demonstrate effectiveness of the proposed choice rule on improving fairness and verify properties of the payment rule.
基金supported by the National Natural Science Foundation of China (Grant Nos. 71231007 and 71373222)
文摘Reverse auctions of PPP projects usually require the bid to specify several characteristics of quality and the concession period to be fulfilled. This paper sets up a summary function of generalized quality, which contributes to reducing the dimensions of information.Thus, the multidimensional reverse auction model of a PPP project can be replaced by a two-dimensional direct mechanism based on the concession period and the generalized quality. Based on the theory of the revelation principle, the feasibility conditions, equilibrium solution and generalized quality requirements of such a mechanism,considering the influence of a variable investment structure are described. Moreover, two feasible multidimensional reverse auctions for implementing such a direct mechanism: Adjusting the scoring function and establishing a special reverse auction rule are built. The analysis shows that in these types of reverse auctions, optimal allocation can be achieved, the social benefit under the incomplete information will be maximized, and the private sector with the highest integrated management level wins the bid. In such a direct mechanism, the investment and financial pressure of the public sector can be reduced.
基金Supported by State Key Lab of Mechanical System and Vibration Project of China(Grant No.MSVZD202008).
文摘Animals can adapt to their surroundings by modifying their trunk morphology,whereas legged robots currently utilize rigid trunks.This study introduces a single-degree-of-freedom(DoF),six-revolute(6R)morphing trunk mechanism designed to equip legged robots with variable-width capabilities.Subsequently,a morphology-aware locomotion learning pipeline,based on reinforcement learning,is proposed for real-time trunk-width deformation and adaptive legged locomotion.The proposed variable-width trunk is integrated into a quadrupedal robot,and the learning pipeline is employed to train the adaptive locomotion controller of this robot.This study has three key contributions:(1)An overconstrained morphing mechanism is designed to achieve single-DoF trunk-width deformation,thereby minimizing power consumption and simplifying motion control.(2)A novel morphology-adaptive learning pipeline is introduced that utilizes adversarial joint-level motion imitation to ensure coordination consistency during morphological adaptation.This method addresses dynamic disturbances and interlimb coordination disruptions caused by width modifications.(3)A historical proprioception-based asymmetric neural network architecture is utilized to attain implicit terrain perception without visual input.Collectively,these developments enable the proposed variable-width legged robot to maintain consistent locomotion across complex terrains and facilitate rapid width deformation in response to environmental changes.Extensive simulation experiments validate the proposed design and control methodology.
基金the fundamental support of the National Natural Science Foundation of China (Nos. 51105013, 51125020)the Beijing Natural Science Foundation of China (No. 3133042)the fundamental support provided by the China Scholarship Council and the State Key Laboratory of Robotics and System (HIT)
文摘The optimization of metamorphic mechanisms is different from that of the conventional mechanisms for its characteristics of multi-configuration. There exist complex coupled design variables and constraints in its multiple different configuration optimization models. To achieve the compatible optimized results of these coupled design variables, an optimization method for metamorphic mechanisms is developed in the paper based on the principle of multidisciplinary design optimization（MDO）. Firstly, the optimization characteristics of the metamorphic mechanism are summarized distinctly by proposing the classification of design variables and constraints as well as coupling interactions among its different configuration optimization models. Further, collaborative optimization technique which is used in MDO is adopted for achieving the overall optimization performance. The whole optimization process is then proposed by constructing a two-level hierarchical scheme with global optimizer and configuration optimizer loops. The method is demonstrated by optimizing a planar five-bar metamorphic mechanism which has two configurations,and results show that it can achieve coordinated optimization results for the same parameters in different configuration optimization models.
基金supported by the National Natural Science Foundation of China,China(52203066,51973157,51673148 and 51678411)the Science and Technology Plans of Tianjin,China(19PTSYJC00010)+3 种基金China Postdoctoral Science Foundation Grant,China(2019M651047)the Tianjin Research Innovation Project for Postgraduate Students,China(2020YJSB062)the Tianjin Municipal College Student’Innovation And Entrepreneurship Training Program,China(202110058052)the National Innovation and Entrepreneurship Training Program for College Students,China(202110058017)。
文摘Non-renewable fossil fuels have led to serious problems such as global warming,environmental pollution,etc.Oxygen electrocatalysis including oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)plays a central role in clean energy conversion,enabling a number of sustainable processes for future air battery technologies.Fluorine,as the most electronegative element(4.0)not only can induce more efficient regulation for the electronic structure,but also can bring more abundant defects and other novel effects in materials selection and preparation for favorable catalysis with respect to the other nonmetal elements.However,an individual and comprehensive overview of fluorine-containing functional materials for oxygen electrocatalysis field is still blank.Therefore,it is very meaningful to review the recent progresses of fluorine-containing oxygen electrocatalysts.In this review,we first systematically summarize the controllable preparation methods and their possible development directions based on fluorine-containing materials from four preparation methods.Due to the strong electron-withdrawing properties of fluorine,its control of the electronic structure can effectively enhance the oxygen electrocatalytic activity of the materials.In addition,the catalytic enhancement effect of fluorine on carbonbased materials also includes the prevent oxidation and the layer peeling,and realizes the precise atomic control.And the catalytic improvement mechanism of fluorine containing metal-based compounds also includes the hydration of metal site,the crystal transformation,and the oxygen vacancy induction.Then,based on their various dimensions(0D–3D),we also have summarized the advantages of different morphologies on oxygen electrocatalytic performances.Finally,the prospects and possible future researching direction of F-containing oxygen electrocatalysts are presented(e.g.,novel pathways,advanced methods for measurement and simulation,field assistance and multi-functions).The review is considered valuable and helpful in exploring the novel designs and mechanism analyses of advanced fluorine-containing electrocatalysts.
文摘We first design and analyze the contour surface of the globoidal indexing cam with the aid of computer, and then do optimum design according to the requirements of dynamics. Finally, we discuss the problem of the pressure angle of the globoidal indexing cam mechanism in detail and put forward a new concept of equivalent pressure angle.
基金support of the National Natural Science Foundation of China(52072236)National Natural Science Foundation of China(52002242)+1 种基金Science&Technology Commission of Shanghai Municipality and Shanghai Engineering Research Center of Ship Intelligent Maintenance and Energy Efficiency(20DZ2252300)Shanghai High-level Local University Innovation Team(Maritime safety&technical support).
文摘Icing as a regular natural phenomenon in life poses a serious threat to human production and life,traditional mechanical deicing,chemical deicing,and other methods have the shortcomings of high pollution,high energy consumption,and low efficiency,which limits their applicability and effectiveness of the scene of the above methods.With the expansion of global economic activities in recent years,the solution to the icing problem has become imminent.As a result,researchers have gradually deepened their studies related to anti-icing.Inspired by the lotus leaf effect,hogwash,polar,marine shellfish,and other natural organisms,anti-icing/deicing coatings can be designed functional biomimetic through both surface micro-nano structures and the physicochemical properties of the material.Superhydrophobic design is based on Young’s wetting equations,Wenzel’s wetting equations,and the Cassie-Baxter model of the superhydrophobic behavior of the interface formed by the liquid droplets and the surface,which prevents the droplets from spreading out and penetration to form heat exchange.The physicochemical properties are based on the slow-release behavior of chemical mediators inside the coating with properties such as super-lubrication and anti-freezing,which reduce the residence time and nucleation temperature of droplets on the surface.The coating effectively blocks the occurrence of icing behavior by passive means such as ultra-low interfacial wetting,interfacial slip,and lowering the freezing point of droplets,which has become a hot research direction.Meanwhile,the active anti-icing of photo-thermal,electro-thermal,phase change and other effects with the passive anti-icing to play a synergistic and complementary role for further enhance the anti-icing effect of the coating.To clarity the design mechanism and preparation process of the anti-icing/ice-removing surfaces,the article firstly classifies and introduces the coatings functioned according to the different mechanisms of action,and sums up the biomimetic super-hydrophobic design,the sacrificial type physicochemical characteristic.The article firstly classifies and introduces the functional types of coatings according to different mechanisms of action,and the latest research progress on the mechanism design of anti-icing coatings and their performance modification such as bionic superhydrophobic design,sacrificial physicochemical property design,microregion modulus control design and multifactorial coupling design were summarized.The problems of single-functionality and imbalance of performance of the existing coating mechanism design were analyzed and discussed,the view of the development trend and outlook of the development and application of icephobic coatings were put forward.
基金supports from the National Natural Science Foundation of China(51775169)the High Level Talent Foundation of Henan University of Technology(31401456)the Innovative Funds Plan of Henan University of Technology(2020ZKCJ26)are gratefully acknowledged.
文摘Solid–liquid separation is widely used in daily life and practical engineering.Traditional industrial filters are prone to clogging,but this rarely occurs in filter-feeding organisms.Inspired by the filter feeding mechanism of balaenid whales and considering the local grooves in the fringes layer,a new bionic filter is produced by 3D printing technology through the bionic design of the parallel channels inside the mouth of balaenid whales.At the same time,a test platform composed of the bionic filter,peristaltic pump,fluid pulse rectifier and water tank is built to carry out the fluid flow pattern dyeing and particle filtration experiments.It is found that fluid separation occurs near the groove structure and local vortices are generated.The vortex control filtration mechanism makes the particles in the front grooves tend to accumulate on the left side,which has a certain anti-clogging effect.Moreover,the increase of flow velocity leads to the enhancement of vortices,which makes the accumulation effect on the left more obvious.This study initially practices the bionic application from biological model to engineering design,and the vortex control anti-clogging filtration mechanism proposed in the study has a wide range of application prospects and values.
基金supported by National Natural Science Foundation of China(Nos.12222513,12105345,12175292,and No.12405178)。
文摘Radio frequency(RF)cavities for advanced storage rings,also known as diffraction-limited storage rings,are under development.To this end,a competitive and promising approach involves normal-conducting continuous wave technology.The design and preliminary test of a 499.654 MHz RF cavity for the Wuhan Advanced Light Source(WALS)based on specific beam parameters were conducted at the SSRF.Multi-objective evolutionary algorithms have been utilized to optimize RF properties,such as the power loss and power density,resulting in better performance in the continuous wave mode.Further improvements were made to suppress multipacting effects in the working area.To operate stably with the beam,higher-order mode dampers were applied to better address the coupling bunch instability than in previous designs,along with thermal analysis to achieve the desired RF performance.Comprehensive simulation studies demonstrated the stable operation of the RF cavity at the defined beam parameters in the WALS design.A prototype RF cavity was then developed,and the RF performance results in a low-power test showed good agreement with the design and simulation,exhibiting readiness for high-power experiments and operation.
文摘Materials mechanics and structural dynamics provide theoretical support for the structural optimization of amusement facilities.The design code system guides the design process,covering aspects such as strength and fatigue life.This paper introduces optimization methods like standardized module interfaces and variable density methods,as well as topics related to finite element simulation,reliability enhancement,innovative practices,and their significance.
文摘As a product of the new century,artificial intelligence has been continuously developed and advanced.It has been applied to many fields,especially in the field of mechanical design and manufacturing.With the support of artificial intelligence,mechanical design and manufacturing can not only reduce input costs but also significantly reduce the demand for labor,playing a positive role in improving the design efficiency and quality of mechanical manufacturing[1].This paper studies how to apply artificial intelligence technology to the mechanical design and production process to achieve greater application and development.
基金College Student Innovation andEntrepreneurship Project(Grant No.:S202414435026)ingkou Institute of Technology campus level research project——Development of food additive supercritical extraction equipment and fluid transmission systemresearch(Grant No.HX202427).
文摘With the acceleration of the global aging process and the increase of cardiovascular ancerebrovascular diseases,more and more patients are paralyzed due to accidents,so theexoskeleton robot began to appear in people's sight,and the lower limb exoskeleton robot withrehabilitation training is also favored by more and more people.In this paper,the structural designand analysis of the lower limb exoskeleton robot are carried out in view of the patients'expectation ofnormal walking.First,gait analysis and structural design of lower limb exoskeleton robot.Based onthe analysis of the walking gait of normal people,the freedom of the three key joints of the lower limbexoskeleton robot hip joint,knee joint and ankle joint is determined.at the same time,according tothe structuralcharacteristics of each joint,the three key joints are modeled respectively,and theoverall model assembly of the lower limb exoskeleton robot is completed.Secondly,the kinematicsanalysis of the lower limb exoskeleton robot was carried out to obtain the relationship between thelinear displacement,linear speed and acceleration of each joint,so as to ensure the coordination ofthe model with the human lower limb movement.Thirdly,the static analysis of typical gait of hipjoint,knee joint and ankle joint is carried out to verify the safety of the design model under thepremise of ensuring the structural strength requirements.Finally,the parts of the model were 3Dprinted,and the rationality of the design was further verified in the process of assembling the model.
