The growing demand for personalized health care,smart wearables,and advanced environmental monitoring has spurred the development of multifunctional materials that combine flexibility,environmental adaptability,and di...The growing demand for personalized health care,smart wearables,and advanced environmental monitoring has spurred the development of multifunctional materials that combine flexibility,environmental adaptability,and diverse functionalities.However,conventional materials often failed to integrate these attributes simultaneously,hindering their applicability in next-generation technologies.Here,we present an organic-inorganic hybrid crystalline material with a unique sandwich-like architecture,in which a flexible organic crystal core is encased by reduced graphene oxide(rGO)and thermoplastic polyurethane(TPU).This strategic integration endows the material with fluorescence,cryogenic flexibility,and electrical conductivity,while also enabling dual sensing and actuation capabilities.The rGO layer facilitates real-time humidity(25-90%RH)and temperature(25-180℃)sensing through environmental interactions,whereas the differential thermal expansion between TPU and the flexible crystal core drives efficient photothermal actuation at-150℃for advanced thermal regulation.The hybrid material exhibits stable performance under extreme conditions,making it a promising candidate for biomedical monitoring,flexible electronics,and energy applications.This work establishes hybrid crystalline materials as versatile and scalable platforms for addressing complex technological demands,paving the way for their application in next-generation multifunctional devices.展开更多
Soft pneumatic structures are promising for the actuation of soft machines,and substantial advances have occurred in their innovative design and functional verification.However,most pneumatic structures lack self-sens...Soft pneumatic structures are promising for the actuation of soft machines,and substantial advances have occurred in their innovative design and functional verification.However,most pneumatic structures lack self-sensing abilities,resulting in a lack of motion state feedback and difficulty in achieving real-time closed-loop control.Herein,a soft pneumatic composite structure(SPCS)with integrated actuation and sensing abilities is developed by combining a bellows-shaped magnetic elastomer and a wire structure.The SPCS can generate an induced voltage under deformation.The SPCS mechanical and magnetoelectric characteristics are studied comprehensively.The SPCS experimental maximum contraction is 27 mm,which is close to the theoretical and numerical results.When the SPCS is actuated by a pressure of-40 kPa,it will generate a peak induced voltage of 1.01 mV.With the increase in magnetic powder content and turns of the spiral wire,the induced voltage also increases.Additionally,two SPCSs are used to develop a self-sensing actuator,which can accurately perceive the bending direction and recognize the magnitude and direction of external force.A self-sensing soft gripper is developed,which can sense the grasping status and predict the width of grasped objects.Furthermore,a smart vehicle detection system composed of two SPCSs is proposed,which can detect the number,speed,and weight of passing vehicles.Consequently,the SPCS has numerous potential applications in soft sensors and self-sensing intelligent soft machines.展开更多
Polymeric microwave actuators combining tissue-like softness with programmablemicrowave-responsive deformation hold great promise for mobile intelligentdevices and bionic soft robots. However, their application is cha...Polymeric microwave actuators combining tissue-like softness with programmablemicrowave-responsive deformation hold great promise for mobile intelligentdevices and bionic soft robots. However, their application is challenged by restricted electromagneticsensitivity and intricate sensing coupling. In this study, a sensitized polymericmicrowave actuator is fabricated by hybridizing a liquid crystal polymer with Ti3C2Tx(MXene). Compared to the initial counterpart, the hybrid polymer exhibits unique spacechargepolarization and interfacial polarization, resulting in significant improvements of230% in the dielectric loss factor and 830% in the apparent efficiency of electromagneticenergy harvest. The sensitized microwave actuation demonstrates as the shortenedresponse time of nearly 10 s, which is merely 13% of that for the initial shape memory polymer. Moreover, the ultra-low content of MXene (upto 0.15 wt%) benefits for maintaining the actuation potential of the hybrid polymer. An innovative self-powered sensing prototype that combinesdriving and piezoelectric polymers is developed, which generates real-time electric potential feedback (open-circuit potential of ~ 3 mV) duringactuation. The polarization-dominant energy conversion mechanism observed in the MXene-polymer hybrid structure furnishes a new approachfor developing efficient electromagnetic dissipative structures and shows potential for advancing polymeric electromagnetic intelligent devices.展开更多
Permanent magnet synchronous motor based electro-mechanical actuation servo drives have widespread applications in the aviation field,such as unmanned aerial vehicle electric servos,electric cabin doors,and mechanical...Permanent magnet synchronous motor based electro-mechanical actuation servo drives have widespread applications in the aviation field,such as unmanned aerial vehicle electric servos,electric cabin doors,and mechanical arms.The performance of the servo drive,which encompasses the response to the torque,efficiency,control bandwidth and the steady-state positioning accuracy,significantly influences the performance of the aviation actuation.Consequently,enhancing the control bandwidth and refining the positioning accuracy of aviation electro-mechanical actuation servo drives have emerged as a focal point of research.This paper investigates the multi-source disturbances present in aviation electro-mechanical actuation servo systems and summarizes recent research on high-performance servo control methods based on active disturbance rejection control(ADRC).We present a comprehensive overview of the research status pertaining to servo control architecture,strategies for suppressing disturbances in the current loop,and ADRC-based strategies for the position loop.We delineate the research challenges and difficulties encountered by aviation electro-mechanical actuation servo drive control technology.展开更多
Underwater robots have emerged as key tools for marine exploration because of their unique ability to traverse and navigate underwater regions,which pose challenges or dangers to human expeditions.Miniature underwater...Underwater robots have emerged as key tools for marine exploration because of their unique ability to traverse and navigate underwater regions,which pose challenges or dangers to human expeditions.Miniature underwater robots are widely employed in marine science,resource surveys,seabed geological investigations,and marine life observations,owing to their compact size,minimal noise,and agile move-ment.In recent years,researchers have developed diverse miniature underwater robots inspired by bion-ics and other disciplines,leading to many landmark achievements such as centimeter-level wireless control,movement speeds up to hundreds of millimeters per second,underwater three-dimensional motion capabilities,robot swarms,and underwater operation robots.This article offers an overview of the actuation methods and locomotion patterns utilized by miniature underwater robots and assesses the advantages and disadvantages of each method.Furthermore,the challenges confronting currently available miniature underwater robots are summarized,and future development trends are explored.展开更多
In this paper,we proposed a compact,lightweight flapping actuation mechanism and a flight control mechanism for a twin-winged,tailless,hover-capable flapping robot named HiFly-Hummingbird,which has a total mass of 14....In this paper,we proposed a compact,lightweight flapping actuation mechanism and a flight control mechanism for a twin-winged,tailless,hover-capable flapping robot named HiFly-Hummingbird,which has a total mass of 14.4 g and a wingspan of 18.8 cm.A four-bar linkage and gears set were adopted to convert the rotation motion of DC motor into flapping oscillation and amplify the flapping amplitude.As well as,a parallel coupled flight control mechanism was designed to implement the aerodynamic moments generation strategies.The proposed flapping actuation mechanism,with a mass of 2.95 g,has been validated to achieve a 168°amplitude at a frequency of 26 Hz with an asymmetrical stroke deviation of 3.5%,operating at a power consumption of 4.05 W.The parallel coupled control mechanism weights 2.14 g(including three servos).Benefit from the nonlinen inverse kinematics model of the parallel coupled control mechanism,the proposed control mechanism exhibits a roll motion range of±10°with an accuracy error of 0.8°and a pitch motion range of±12°with an accuracy error of 0.6°.The proposed mechanical systems are beneficial to lightweight design,manufacture and assemble under stringent size,weight and power(SWaP)constraints of flapping wing micro air vehicles(FW-MAVs),and possess favorable efficiency and accuracy.Relying on the hardware control circuit and feed-back attitude control algorithm,the robot hummingbird successfully achieved untethered lifting off and reached a maximum flight altitude of 4 m in several flight tests,demonstrating that the proposed mechanical designs of the flapping robot platform effectively enhances the miniaturization and light-weighting of the hummingbird-like FW-MAVs under the conditions of meeting the propulsion and control requirements for lifting off.展开更多
This work proposes a bioinspired hierarchical actuation strategy based on liquid crystal elastomers(LCEs),inspired by the helical topological dynamic adaptation mechanism of plant tendrils,to overcome the bottleneck o...This work proposes a bioinspired hierarchical actuation strategy based on liquid crystal elastomers(LCEs),inspired by the helical topological dynamic adaptation mechanism of plant tendrils,to overcome the bottleneck of precise anisotropic control in LCEs.Mechanically pre-programmed hierarchical LCE structures responsive to near-infrared(NIR)light were fabricated:the oriented constrained actuator achieves asymmetric contraction under NIR irradiation,enabling reversible switching between helix and planar morphologies with multi-terrain grasping capability;the biomimetic vine-like helical actuator,composed of Ag nanowire photothermal layers combined with helical LCE,utilizes temperaturegradient-induced phase transition wave propagation to achieve NIR-controlled climbing motion;the M?bius topology actuator realizes reversible deformation or self-locking states by tuning the twist angle(180°/360°);based on these,a bioinspired koala-like concentric soft robot was constructed,successfully demonstrating tree trunk climbing.This study reveals that artificial helical stretching significantly enhances the molecular chain orientation of LCEs(surpassing uniaxial stretching),reaching up to 1000%pre-strain,and the Ag NWs/LCE/PI(Polyimide)tri-layer structure achieves efficient photothermal-mechanical energy conversion via localized surface plasmon resonance(LSPR).This study provides a new paradigm for soft robotics material design and topological programming,demonstrating the potential for remote operation and adaptive grasping.展开更多
Locomotion performance degradation after carrying payloads is a significant challenge for insect-scale microrobots.Previously,a legged microrobot named BHMbot with a high load-carrying capacity based on front-leg actu...Locomotion performance degradation after carrying payloads is a significant challenge for insect-scale microrobots.Previously,a legged microrobot named BHMbot with a high load-carrying capacity based on front-leg actuation configuration and efficient running gait was proposed.However,insects,mammals and reptiles in nature typically use their powerful rear legs to achieve rapid running gaits for predation or risk evasion.In this work,the load-carrying capacity of the BHMbots with front-leg actuation and rear-leg actuation configurations is comparatively studied.Simulations based on a dynamic model with four degrees of freedom,along with experiments,have been conducted to analyze the locomotion characteristics of the two configurations under different payload masses.Both simulation and experimental results indicate that the load-carrying capacity of the microrobots is closely related to their actuation configurations,which leads to different dynamic responses of the microrobots after carrying varying payload masses.For microrobots with body lengths of 15 mm,the rear-leg actuation configuration exhibits a 31.2%enhancement in running speed compared to the front-leg actuation configuration when unloaded.Conversely,when carrying payloads exceeding 5.7 times the body mass(350 mg),the rear-leg actuation configuration demonstrates an 80.1%reduction in running speed relative to the front-leg actuation configuration under the same payload conditions.展开更多
Stimuli-responsive shape-changing materials,particularly hydrogel and liquid crystal elastomer(LCE),have demonstrated significant potential for applications across various fields.Although intricate deformation and act...Stimuli-responsive shape-changing materials,particularly hydrogel and liquid crystal elastomer(LCE),have demonstrated significant potential for applications across various fields.Although intricate deformation and actuation behaviors have been obtained in either hydrogels or LCEs,they typically undergo reversible shape change only once(e.g.,one expansion plus one contraction)during one heating/cooling cycle.Herein,we report a study of a novel liquid crystalline hydrogel(LCH)and the achievement of dual actuation in a single heating/cooling cycle by integrating the characteristics of thermoresponsive hydrogel and LCE.The dual actuation behavior arises from the reversible volume phase transition of poly(N-isopropylacrylamide)(PNIPAM)and the reversible order-disorder phase transition of LC mesogens in the LCH.Due to a temperature window separating the two transitions belonging to PNIPAM and LCE,LCH actuator can sequentially execute their respective actuation,thus deforming reversibly twice,during a heating/cooling cycle.The relative actuation degree of the two mechanisms is influenced by the mass ratio of PNIPAM to LCE in the LCH.Moreover,the initial shape of a bilayer actuator made with an active LCH layer and a passive polymer layer can be altered through hydration or dehydration of PNIPAM,which further modifies the dual actuation induced deformation.This work provides an example that shows the interest of developing LCH actuators.展开更多
Self-propelled robots have attracted significant attention due to their remarkable ability to navigate confined terrains.These robots usually have deformable structures while having discontinuous contact forces with t...Self-propelled robots have attracted significant attention due to their remarkable ability to navigate confined terrains.These robots usually have deformable structures while having discontinuous contact forces with the ground,resulting in a complex nonlinear system.To provide a solid foundation for the locomotion prediction and optimization for the self-propelled robots,it is necessary to conduct dynamic modelling and locomotion analysis of the robot.Motivated by these issues,this paper proposes a vibration-driven surrogate dynamic model for a deformable self-propelled robot and presents a detailed dynamic analysis.The surrogate dynamic model is employed to classify various types of stick-slip locomotion.Subsequently,the corresponding experiment demonstrates that the surrogate dynamic model effectively predicts the locomotion of the robot,particularly three types of stick-slip locomotion induced by discontinuous friction.Finally,a multi-objective coordinated optimization regarding the locomotion velocity,the cost of transport,and the energy conversion rate of the self-propelled robot is conducted,aiming to comprehensively enhance the robot’s locomotion performance.Additionally,suggestions for the selection of actuation parameters are presented.展开更多
This paper studies cooperative robust parallel operation of multiple actuators over an undirected communication graph.The plant is modeled as an uncertain linear system,and the actuators are linear and identical.Based...This paper studies cooperative robust parallel operation of multiple actuators over an undirected communication graph.The plant is modeled as an uncertain linear system,and the actuators are linear and identical.Based on the internal model principle,a distributed dynamic output feedback control law is proposed to achieve both robust output regulation of the closed-loop system and plant input sharing among the actuators.A practical example of five motors cooperatively driving an uncertain shaft under an external load torque is presented to show the effectiveness of the proposed control law.展开更多
Reducing the peak actuating force(PAF)and parasitic displacement is of high significance for improving the performance of compliant parallel mechanisms(CPMs).In this study,a 2-DOF 4-4R compliant parallel pointing mech...Reducing the peak actuating force(PAF)and parasitic displacement is of high significance for improving the performance of compliant parallel mechanisms(CPMs).In this study,a 2-DOF 4-4R compliant parallel pointing mechanism(4-4R CPPM)was used as the object,and the actuating force of the mechanism was optimized through redundant actuation.This was aimed at minimizing the PAF and parasitic displacement.First,a kinetostatic model of the redundantly actuated 4-4R CPPM was established to reveal the relationship between the input forces/displacements and the output displacements of the mobile platform.Subsequently,based on the established kinetostatic model,methods for optimizing the actuating force distribution with the aim of minimizing the PAF and parasitic displacement were introduced successively.Second,a simulated example of a mobile platform’s spatial pointing trajectory validated the accuracy of the kinetostatic model.The results show a less than 0.9%relative error between the analytical and finite element(FE)results,and the high consistency indicates the accuracy of the kinetostatic model.Then,the effectiveness of the method in minimizing the PAF and parasitic displacement was validated using two simulated examples.The results indicate that compared with the non-redundant actuation case,the PAF of the mechanism could be reduced by up to 50%,and the parasitic displacement was reduced by approximately three-four orders of magnitude by means of redundant actuation combined with the optimal distribution of the actuating force.As expected,with the reduction in parasitic displacement,the FE-results of the output angular displacements(θ_(x) andθ_(z))of the mobile platform were closer to the target oscillation trajectory.This further verified that the reduction in parasitic displacement is indeed effective in improving the motion accuracy of the mechanism.The advantage of this proposed method is that it reduces the PAF and parasitic displacement from the perspective of the actuating force control strategy,without the requirement of structural changes to the original mechanism.展开更多
Soft actuators,capable of producing mechanical work in response to external stimuli,have potential applications in robotics and exoskeletons.However,they face major challenges related to energy supply,especially in lo...Soft actuators,capable of producing mechanical work in response to external stimuli,have potential applications in robotics and exoskeletons.However,they face major challenges related to energy supply,especially in long-distance and miniaturized environments.Fuel-driven actuators offer a promising solution by enabling the conversion of chemical energy into mechanical energy,supporting selfsustaining operations.Chemical energy from fuel can be converted into mechanical energy either directly or indirectly through methods such as electron transfer-induced charge injection,structural changes,fuel-to-electricity conversion,fuel combustioninduced heat,or fuel-induced pneumatic actuation.This paper provides a comprehensive review of recent developments in fuel-powered actuators,covering their fundamental principles,advancements,and challenges.It concludes with an outlook for miniaturized and autonomous robots,highlighting the great potential of integrating fuel-powered actuators.展开更多
Azobenzene-based polymer actuators show great promise for photoactuation owing to their unique photoisomerization behavior and tailorable molecular programmability.However,conventional systems are limited by inadequat...Azobenzene-based polymer actuators show great promise for photoactuation owing to their unique photoisomerization behavior and tailorable molecular programmability.However,conventional systems are limited by inadequate mechanical robustness,self-healing,and recyclability,hindering their practical implementation.Herein,we present a high-performance azobenzene-functionalized polyurethane(AzoPU)elastomer actuator designed via molecular engineering of photoactive azobenzene moieties and dynamic disulfide bonds.AzoPU exhibits exceptional mechanical properties with retained performance after multiple reshaping cycles,enabled by well-engineered hard-soft segments and synergistic stress dissipation from weak covalent bonds/hierarchical hydrogen bonds.It achieves over 93%self-healing efficiency at room temperature owing to the synergistic interplay of disulfide bonds in the polymer backbone and intermolecular hydrogen bonds.Furthermore,it demonstrates remarkable light-triggered actuation behavior,achieving a phototropic bending angle exceeding 180°toward the light source within 45 s.To showcase its practical potential,proof-of-concept photoactuated devices with flower-,hook-,and gripper-like and local-orientation processed strip-shaped structures were fabricated,which exhibited rapid and reversible light-triggered deformation.This study proposes a novel strategy for the development of intelligent polymeric materials that integrate light responsiveness,self-healing,and recyclability,thus holding great promise for applications in flexible electronics,smart actuators,and sustainable functional materials.展开更多
Microrobotic systems are emerging as transformative technology for minimally invasive medicine,driven by innovations in actuation mechanisms,advanced fabrication paradigms,and multifunctional system integration.This c...Microrobotic systems are emerging as transformative technology for minimally invasive medicine,driven by innovations in actuation mechanisms,advanced fabrication paradigms,and multifunctional system integration.This comprehensive review analyzes the evolution of microrobotic technologies through three critical dimensions:(1)actuation modalities,including magnetic,optical,acoustic,chemical,and biological actuation,with a focus on the synergistic advantages of hybrid actuation strategies in complex internal physiological environments;(2)Fabrication methods cover technolo-gies such as photolithography,microinjection molding,self-assembly,and 3D printing,emphasizing innovative strategies involving multi-technology integration and collaborative manufacturing of bio/non-bio hybrid materials;(3)Internal phys-iological applications involve disease diagnosis,targeted drug delivery,minimally invasive surgery,tissue engineering,and cell manipulation,highlighting the broad prospects of microrobots in precision medicine.Despite remarkable progress,critical challenges remain,including low actuation efficiency,as seen in acoustic systems,limited biocompatibility,exem-plified by the toxicity of hydrogen peroxide in chemical actuation,delayed clinical translation,and other related challenges that must be addressed to advance the field.展开更多
The soft actuator is characterized by high safety,flexibility,and adaptability.It is capable of both active and passive defor-mations.This paper presents a discrete degree of freedom(DOF)method for soft actuators to r...The soft actuator is characterized by high safety,flexibility,and adaptability.It is capable of both active and passive defor-mations.This paper presents a discrete degree of freedom(DOF)method for soft actuators to reveal DOF characteristics.The method draws on the superposition mechanism of the deformation characteristics of the sarcomere in the skeletal muscles of living organisms.Firstly,the multi-DOF deformation characteristics of the soft actuator are discretized into superimposed combinations of single-DOF micro-units.Then,the soft actuator was determined to contain deformation characteristics such as extension-contraction,bending,and twisting.Eighteen types of micro-units with basic deforma-tion characteristics were obtained depending on the axis and orientation.Further,the mapping relationship between the combination of micro-units and the motion characteristics of the soft actuator based on the GF set theory was established.Finally,an active-passive DOF co-structured soft actuator(APCSA)was developed.The graphical approach analyzes the experimental results,and it can be concluded that active and passive DOFs can coexist in the composite deformation of the soft actuator.展开更多
Plasma flow control is an active flow control technology that based on the plasma aerodynamic actuation. It can be used to enhance the aerodynamic characteristics of aircraft and propulsion systems. To study the pheno...Plasma flow control is an active flow control technology that based on the plasma aerodynamic actuation. It can be used to enhance the aerodynamic characteristics of aircraft and propulsion systems. To study the phenomena occurring in plasma aerodynamic actuation and the mechanism of plasma flow control, the induced flow velocity of the plasma aerodynamic actuator is experimentally investigated under a variety of parameter conditions. The results indicate that plasma aerodynamic actuation accelerates the near surface air at velocities of a few meters per second, and there is an angle about 5° between the mainstream and the actuator wall and a spiral vortex is formed when the induced flow is moving along the wall. Besides, with the fixed frequency, the induced flow velocity increases linearly with the applied voltage, but it is insensitive to the frequency when the applied voltage is fixed. And the configuration is an effective factor for the performance of the plasma aerodynamic actuator.展开更多
Electrohydrostatic actuator（EHA） is a type of power-by-wire actuator that is widely implemented in the aerospace industry for flight control, landing gears, thrust reversers, thrust vector control, and space robots....Electrohydrostatic actuator（EHA） is a type of power-by-wire actuator that is widely implemented in the aerospace industry for flight control, landing gears, thrust reversers, thrust vector control, and space robots. This paper presents the development and evaluation of positionbased impedance control（PBIC） for an EHA. Impedance control provides the actuator with compliance and facilitates the interaction with the environment. Most impedance control applications utilize electrical or valve-controlled hydraulic actuators, whereas this work realizes impedance control via a compact and efficient EHA. The structures of the EHA and PBIC are firstly introduced. A mathematical model of the actuation system is established, and values of its coefficients are identified by particle swarm optimization. This model facilitates the development of a position controller and the selection of target impedance parameters. A nonlinear proportional-integral position controller is developed for the EHA to achieve the accurate positioning requirement of PBIC. The controller compensates for the adverse effect of stiction, and a position accuracy of 0.08 mm is attained.Various experimental results are presented to verify the applicability of PBIC to the EHA. The compliance of the actuator is demonstrated in an impact test.展开更多
The optional types of power source and actuator in the aircraft are more and more diverse due to fast development in more electric technology, which makes the combinations of different power sources and actuators beco...The optional types of power source and actuator in the aircraft are more and more diverse due to fast development in more electric technology, which makes the combinations of different power sources and actuators become extremely complex in the architecture optimization process of airborne actuation system. The traditional ＂trial and error＂ method cannot satisfy the design demands. In this paper, firstly, the composition of more electric aircraft （MEA） flight control actuation system （FCAS） is introduced, and the possible architecture quantity is calculated. Secondly, the evaluation criteria of FCAS architecture with respect to safe reliability, weight and efficiency are proposed, and the evaluation criteria values are calculated in the case that each control surface adopts the same actuator configuration. Finally, the optimization results of MEA FCAS architecture are obtained by applying genetic algorithm （GA）. Compared to the traditional actuation system architecture, which only adopts servo valve controlled hydraulic actuators, the weight of the optimized more electric actuation system architecture can be reduced by 6%, and the efficiency can be improved by 30% based on the safe reliability requirements.展开更多
To discover the characteristic of separated flows and mechanism of plasma flow control on a highly loaded compressor cascade, numerical investigation is conducted. The simulation method is validated by oil flow visual...To discover the characteristic of separated flows and mechanism of plasma flow control on a highly loaded compressor cascade, numerical investigation is conducted. The simulation method is validated by oil flow visualization and pressure distribution. The loss coefficients, streamline patterns, and topology structure as well as vortex structure are analyzed. Results show that the numbers of singular points increase and three pairs of additional singular points of topology structure on solid surface generate with the increase of angle of attack, and the total pressure loss increases greatly. There are several principal vortices inside the cascade passage. The pressure side leg of horse-shoe vortex coexists within a specific region together with passage vortex, but finally merges into the latter. Corner vortex exists independently and does not evolve from the suction side leg of horse-shoe vortex. One pair of radial coupling-vortex exists near blade trailing edge and becomes the main part of backflow on the suction surface. Passage vortex interacts with the concentrated shedding vortex and they evolve into a large-scale vortex rotating in the direction opposite to passage vortex. The singular points and separation lines represent the basic separation feature of cascade passage. Plasma actuation has better effect at low freestream velocity, and the relative reductions of pitch-averaged total pressure loss coefficient with different actuation layouts of five and two pairs of electrodes are up to 30.8% and 26.7% while the angle of attack is 2~. Plasma actuation changes the local topology structure, but does not change the number relation of singular points. One pair of additional singular point of topology structure generates with plasma actuation and one more reattachment line appears, both of which break the separation line on the suction surface.展开更多
基金support from the National Natural Science Foundation of China(52373181 and 52173164)the Natural Science Foundation of Jilin Province(20250102120JC and 20230101038JC)+1 种基金the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(GZB20240259)the Project funded by China Postdoctoral Science Foundation(2024M761121 and 2025T180139).
文摘The growing demand for personalized health care,smart wearables,and advanced environmental monitoring has spurred the development of multifunctional materials that combine flexibility,environmental adaptability,and diverse functionalities.However,conventional materials often failed to integrate these attributes simultaneously,hindering their applicability in next-generation technologies.Here,we present an organic-inorganic hybrid crystalline material with a unique sandwich-like architecture,in which a flexible organic crystal core is encased by reduced graphene oxide(rGO)and thermoplastic polyurethane(TPU).This strategic integration endows the material with fluorescence,cryogenic flexibility,and electrical conductivity,while also enabling dual sensing and actuation capabilities.The rGO layer facilitates real-time humidity(25-90%RH)and temperature(25-180℃)sensing through environmental interactions,whereas the differential thermal expansion between TPU and the flexible crystal core drives efficient photothermal actuation at-150℃for advanced thermal regulation.The hybrid material exhibits stable performance under extreme conditions,making it a promising candidate for biomedical monitoring,flexible electronics,and energy applications.This work establishes hybrid crystalline materials as versatile and scalable platforms for addressing complex technological demands,paving the way for their application in next-generation multifunctional devices.
基金supported by the National Natural Science Foundation of China(Grant No.52405267)the Jiangxi Provincial Natural Science Foundation(Grant Nos.20242BAB25257,20232BAB214050)+1 种基金the China Postdoctoral Science Foundation(Grant No.2024M760877)the Natural Science Foundation of Hunan Province(Grant No.2025JJ60369)。
文摘Soft pneumatic structures are promising for the actuation of soft machines,and substantial advances have occurred in their innovative design and functional verification.However,most pneumatic structures lack self-sensing abilities,resulting in a lack of motion state feedback and difficulty in achieving real-time closed-loop control.Herein,a soft pneumatic composite structure(SPCS)with integrated actuation and sensing abilities is developed by combining a bellows-shaped magnetic elastomer and a wire structure.The SPCS can generate an induced voltage under deformation.The SPCS mechanical and magnetoelectric characteristics are studied comprehensively.The SPCS experimental maximum contraction is 27 mm,which is close to the theoretical and numerical results.When the SPCS is actuated by a pressure of-40 kPa,it will generate a peak induced voltage of 1.01 mV.With the increase in magnetic powder content and turns of the spiral wire,the induced voltage also increases.Additionally,two SPCSs are used to develop a self-sensing actuator,which can accurately perceive the bending direction and recognize the magnitude and direction of external force.A self-sensing soft gripper is developed,which can sense the grasping status and predict the width of grasped objects.Furthermore,a smart vehicle detection system composed of two SPCSs is proposed,which can detect the number,speed,and weight of passing vehicles.Consequently,the SPCS has numerous potential applications in soft sensors and self-sensing intelligent soft machines.
基金supported by the National Natural Science Foundation of China(No.52373280,52177014,51977009,52273257)。
文摘Polymeric microwave actuators combining tissue-like softness with programmablemicrowave-responsive deformation hold great promise for mobile intelligentdevices and bionic soft robots. However, their application is challenged by restricted electromagneticsensitivity and intricate sensing coupling. In this study, a sensitized polymericmicrowave actuator is fabricated by hybridizing a liquid crystal polymer with Ti3C2Tx(MXene). Compared to the initial counterpart, the hybrid polymer exhibits unique spacechargepolarization and interfacial polarization, resulting in significant improvements of230% in the dielectric loss factor and 830% in the apparent efficiency of electromagneticenergy harvest. The sensitized microwave actuation demonstrates as the shortenedresponse time of nearly 10 s, which is merely 13% of that for the initial shape memory polymer. Moreover, the ultra-low content of MXene (upto 0.15 wt%) benefits for maintaining the actuation potential of the hybrid polymer. An innovative self-powered sensing prototype that combinesdriving and piezoelectric polymers is developed, which generates real-time electric potential feedback (open-circuit potential of ~ 3 mV) duringactuation. The polarization-dominant energy conversion mechanism observed in the MXene-polymer hybrid structure furnishes a new approachfor developing efficient electromagnetic dissipative structures and shows potential for advancing polymeric electromagnetic intelligent devices.
基金supported by the National Natural Science Foundation of China(Nos.52177059 and 52407064).
文摘Permanent magnet synchronous motor based electro-mechanical actuation servo drives have widespread applications in the aviation field,such as unmanned aerial vehicle electric servos,electric cabin doors,and mechanical arms.The performance of the servo drive,which encompasses the response to the torque,efficiency,control bandwidth and the steady-state positioning accuracy,significantly influences the performance of the aviation actuation.Consequently,enhancing the control bandwidth and refining the positioning accuracy of aviation electro-mechanical actuation servo drives have emerged as a focal point of research.This paper investigates the multi-source disturbances present in aviation electro-mechanical actuation servo systems and summarizes recent research on high-performance servo control methods based on active disturbance rejection control(ADRC).We present a comprehensive overview of the research status pertaining to servo control architecture,strategies for suppressing disturbances in the current loop,and ADRC-based strategies for the position loop.We delineate the research challenges and difficulties encountered by aviation electro-mechanical actuation servo drive control technology.
基金supported by the Natural Science Foundation of Jiangsu Province,China(BK20220813)the Fundamental Research Funds for the Central Universities(2242023K40014).
文摘Underwater robots have emerged as key tools for marine exploration because of their unique ability to traverse and navigate underwater regions,which pose challenges or dangers to human expeditions.Miniature underwater robots are widely employed in marine science,resource surveys,seabed geological investigations,and marine life observations,owing to their compact size,minimal noise,and agile move-ment.In recent years,researchers have developed diverse miniature underwater robots inspired by bion-ics and other disciplines,leading to many landmark achievements such as centimeter-level wireless control,movement speeds up to hundreds of millimeters per second,underwater three-dimensional motion capabilities,robot swarms,and underwater operation robots.This article offers an overview of the actuation methods and locomotion patterns utilized by miniature underwater robots and assesses the advantages and disadvantages of each method.Furthermore,the challenges confronting currently available miniature underwater robots are summarized,and future development trends are explored.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences under Grant XDA2202050partially supported by the Youth Innovation Promotion Association of Chinese Academy of Sciences under Grant 2013213.
文摘In this paper,we proposed a compact,lightweight flapping actuation mechanism and a flight control mechanism for a twin-winged,tailless,hover-capable flapping robot named HiFly-Hummingbird,which has a total mass of 14.4 g and a wingspan of 18.8 cm.A four-bar linkage and gears set were adopted to convert the rotation motion of DC motor into flapping oscillation and amplify the flapping amplitude.As well as,a parallel coupled flight control mechanism was designed to implement the aerodynamic moments generation strategies.The proposed flapping actuation mechanism,with a mass of 2.95 g,has been validated to achieve a 168°amplitude at a frequency of 26 Hz with an asymmetrical stroke deviation of 3.5%,operating at a power consumption of 4.05 W.The parallel coupled control mechanism weights 2.14 g(including three servos).Benefit from the nonlinen inverse kinematics model of the parallel coupled control mechanism,the proposed control mechanism exhibits a roll motion range of±10°with an accuracy error of 0.8°and a pitch motion range of±12°with an accuracy error of 0.6°.The proposed mechanical systems are beneficial to lightweight design,manufacture and assemble under stringent size,weight and power(SWaP)constraints of flapping wing micro air vehicles(FW-MAVs),and possess favorable efficiency and accuracy.Relying on the hardware control circuit and feed-back attitude control algorithm,the robot hummingbird successfully achieved untethered lifting off and reached a maximum flight altitude of 4 m in several flight tests,demonstrating that the proposed mechanical designs of the flapping robot platform effectively enhances the miniaturization and light-weighting of the hummingbird-like FW-MAVs under the conditions of meeting the propulsion and control requirements for lifting off.
基金financially supported by the National Natural Science Foundation of China(Nos.52275290 and 51905222)the Research Project of the State Key Laboratory of Mechanical System and Oscillation(No.MSV202419)+2 种基金Major Program of the National Natural Science Foundation of China for Basic Theory and Key Technology of Tri-Co Robots(No.92248301)Opening Project of the Key Laboratory of Bionic Engineering(Ministry of Education),Jilin University(No.KF2023006)Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.SJCX23_2091)。
文摘This work proposes a bioinspired hierarchical actuation strategy based on liquid crystal elastomers(LCEs),inspired by the helical topological dynamic adaptation mechanism of plant tendrils,to overcome the bottleneck of precise anisotropic control in LCEs.Mechanically pre-programmed hierarchical LCE structures responsive to near-infrared(NIR)light were fabricated:the oriented constrained actuator achieves asymmetric contraction under NIR irradiation,enabling reversible switching between helix and planar morphologies with multi-terrain grasping capability;the biomimetic vine-like helical actuator,composed of Ag nanowire photothermal layers combined with helical LCE,utilizes temperaturegradient-induced phase transition wave propagation to achieve NIR-controlled climbing motion;the M?bius topology actuator realizes reversible deformation or self-locking states by tuning the twist angle(180°/360°);based on these,a bioinspired koala-like concentric soft robot was constructed,successfully demonstrating tree trunk climbing.This study reveals that artificial helical stretching significantly enhances the molecular chain orientation of LCEs(surpassing uniaxial stretching),reaching up to 1000%pre-strain,and the Ag NWs/LCE/PI(Polyimide)tri-layer structure achieves efficient photothermal-mechanical energy conversion via localized surface plasmon resonance(LSPR).This study provides a new paradigm for soft robotics material design and topological programming,demonstrating the potential for remote operation and adaptive grasping.
基金supported in part by Beijing Natural Science Foundation under Grant 3232010in part by the National Natural Science Foundation of China under Grant 12002017+2 种基金in part by AECC Industry-university Collocation Fund under Grant HFZL2023CXY026in part by Beihang Outstanding Young Scholars Project under Grant YWF-23-L-1201in part by 111 Project under Grant B08009.
文摘Locomotion performance degradation after carrying payloads is a significant challenge for insect-scale microrobots.Previously,a legged microrobot named BHMbot with a high load-carrying capacity based on front-leg actuation configuration and efficient running gait was proposed.However,insects,mammals and reptiles in nature typically use their powerful rear legs to achieve rapid running gaits for predation or risk evasion.In this work,the load-carrying capacity of the BHMbots with front-leg actuation and rear-leg actuation configurations is comparatively studied.Simulations based on a dynamic model with four degrees of freedom,along with experiments,have been conducted to analyze the locomotion characteristics of the two configurations under different payload masses.Both simulation and experimental results indicate that the load-carrying capacity of the microrobots is closely related to their actuation configurations,which leads to different dynamic responses of the microrobots after carrying varying payload masses.For microrobots with body lengths of 15 mm,the rear-leg actuation configuration exhibits a 31.2%enhancement in running speed compared to the front-leg actuation configuration when unloaded.Conversely,when carrying payloads exceeding 5.7 times the body mass(350 mg),the rear-leg actuation configuration demonstrates an 80.1%reduction in running speed relative to the front-leg actuation configuration under the same payload conditions.
基金financial support from the Natural Sciences and Engineering Research Council of Canada(NSERC),le Fonds de recherche du Québec:Nature et technologies(FRQNT),and The Centre québécois sur les matériaux fonctionnels.
文摘Stimuli-responsive shape-changing materials,particularly hydrogel and liquid crystal elastomer(LCE),have demonstrated significant potential for applications across various fields.Although intricate deformation and actuation behaviors have been obtained in either hydrogels or LCEs,they typically undergo reversible shape change only once(e.g.,one expansion plus one contraction)during one heating/cooling cycle.Herein,we report a study of a novel liquid crystalline hydrogel(LCH)and the achievement of dual actuation in a single heating/cooling cycle by integrating the characteristics of thermoresponsive hydrogel and LCE.The dual actuation behavior arises from the reversible volume phase transition of poly(N-isopropylacrylamide)(PNIPAM)and the reversible order-disorder phase transition of LC mesogens in the LCH.Due to a temperature window separating the two transitions belonging to PNIPAM and LCE,LCH actuator can sequentially execute their respective actuation,thus deforming reversibly twice,during a heating/cooling cycle.The relative actuation degree of the two mechanisms is influenced by the mass ratio of PNIPAM to LCE in the LCH.Moreover,the initial shape of a bilayer actuator made with an active LCH layer and a passive polymer layer can be altered through hydration or dehydration of PNIPAM,which further modifies the dual actuation induced deformation.This work provides an example that shows the interest of developing LCH actuators.
基金supported by the National Natural Science Foundation of China(Grant Nos.11932015,12072237,and 12372022)the Shanghai Gaofeng Project for University Academic Program Development,and the Fundamental Research Funds for the Central Universities(Grant No.22120220590).
文摘Self-propelled robots have attracted significant attention due to their remarkable ability to navigate confined terrains.These robots usually have deformable structures while having discontinuous contact forces with the ground,resulting in a complex nonlinear system.To provide a solid foundation for the locomotion prediction and optimization for the self-propelled robots,it is necessary to conduct dynamic modelling and locomotion analysis of the robot.Motivated by these issues,this paper proposes a vibration-driven surrogate dynamic model for a deformable self-propelled robot and presents a detailed dynamic analysis.The surrogate dynamic model is employed to classify various types of stick-slip locomotion.Subsequently,the corresponding experiment demonstrates that the surrogate dynamic model effectively predicts the locomotion of the robot,particularly three types of stick-slip locomotion induced by discontinuous friction.Finally,a multi-objective coordinated optimization regarding the locomotion velocity,the cost of transport,and the energy conversion rate of the self-propelled robot is conducted,aiming to comprehensively enhance the robot’s locomotion performance.Additionally,suggestions for the selection of actuation parameters are presented.
基金Supported by the Shenzhen Key Laboratory of Control Theory and Intelligent Systems (ZDSYS20220330161800001)the National Natural Science Foundation of China (62303207)the Guangdong Basic and Applied Basic Research Foundation (2024A1515010725)。
文摘This paper studies cooperative robust parallel operation of multiple actuators over an undirected communication graph.The plant is modeled as an uncertain linear system,and the actuators are linear and identical.Based on the internal model principle,a distributed dynamic output feedback control law is proposed to achieve both robust output regulation of the closed-loop system and plant input sharing among the actuators.A practical example of five motors cooperatively driving an uncertain shaft under an external load torque is presented to show the effectiveness of the proposed control law.
基金Supported by Key Project of Hubei Provincial Department of Education Research Program(Grant No.D20211401).
文摘Reducing the peak actuating force(PAF)and parasitic displacement is of high significance for improving the performance of compliant parallel mechanisms(CPMs).In this study,a 2-DOF 4-4R compliant parallel pointing mechanism(4-4R CPPM)was used as the object,and the actuating force of the mechanism was optimized through redundant actuation.This was aimed at minimizing the PAF and parasitic displacement.First,a kinetostatic model of the redundantly actuated 4-4R CPPM was established to reveal the relationship between the input forces/displacements and the output displacements of the mobile platform.Subsequently,based on the established kinetostatic model,methods for optimizing the actuating force distribution with the aim of minimizing the PAF and parasitic displacement were introduced successively.Second,a simulated example of a mobile platform’s spatial pointing trajectory validated the accuracy of the kinetostatic model.The results show a less than 0.9%relative error between the analytical and finite element(FE)results,and the high consistency indicates the accuracy of the kinetostatic model.Then,the effectiveness of the method in minimizing the PAF and parasitic displacement was validated using two simulated examples.The results indicate that compared with the non-redundant actuation case,the PAF of the mechanism could be reduced by up to 50%,and the parasitic displacement was reduced by approximately three-four orders of magnitude by means of redundant actuation combined with the optimal distribution of the actuating force.As expected,with the reduction in parasitic displacement,the FE-results of the output angular displacements(θ_(x) andθ_(z))of the mobile platform were closer to the target oscillation trajectory.This further verified that the reduction in parasitic displacement is indeed effective in improving the motion accuracy of the mechanism.The advantage of this proposed method is that it reduces the PAF and parasitic displacement from the perspective of the actuating force control strategy,without the requirement of structural changes to the original mechanism.
基金Financial support from the program of the National Natural Science Foundation of China(Grant no.52475059)Major Program of National Natural Science Founda-tion of China(NSFC)for Basic Theory and Key Technology of Tri-Co Robots(92248301)+3 种基金the Postdoctoral Research Foundation of China(No.2024M751167)the Young Elite Scientists Sponsorship Program by CAST(2023QNRC001)Jiangsu Province Natural Science Foundation(No.BK20240155)supported by the Nano&Material Technology Development Program through the National Research Foundation of Korea(NRF),funded by the Ministry of Science and ICT(RS2024-00406534,RS-2025-25442809)。
文摘Soft actuators,capable of producing mechanical work in response to external stimuli,have potential applications in robotics and exoskeletons.However,they face major challenges related to energy supply,especially in long-distance and miniaturized environments.Fuel-driven actuators offer a promising solution by enabling the conversion of chemical energy into mechanical energy,supporting selfsustaining operations.Chemical energy from fuel can be converted into mechanical energy either directly or indirectly through methods such as electron transfer-induced charge injection,structural changes,fuel-to-electricity conversion,fuel combustioninduced heat,or fuel-induced pneumatic actuation.This paper provides a comprehensive review of recent developments in fuel-powered actuators,covering their fundamental principles,advancements,and challenges.It concludes with an outlook for miniaturized and autonomous robots,highlighting the great potential of integrating fuel-powered actuators.
基金financially supported by the National Natural Science Foundation of China(No.52503154)Shandong Provincial Natural Science Foundation(Nos.ZR2022MB034 and ZR2025QC512)。
文摘Azobenzene-based polymer actuators show great promise for photoactuation owing to their unique photoisomerization behavior and tailorable molecular programmability.However,conventional systems are limited by inadequate mechanical robustness,self-healing,and recyclability,hindering their practical implementation.Herein,we present a high-performance azobenzene-functionalized polyurethane(AzoPU)elastomer actuator designed via molecular engineering of photoactive azobenzene moieties and dynamic disulfide bonds.AzoPU exhibits exceptional mechanical properties with retained performance after multiple reshaping cycles,enabled by well-engineered hard-soft segments and synergistic stress dissipation from weak covalent bonds/hierarchical hydrogen bonds.It achieves over 93%self-healing efficiency at room temperature owing to the synergistic interplay of disulfide bonds in the polymer backbone and intermolecular hydrogen bonds.Furthermore,it demonstrates remarkable light-triggered actuation behavior,achieving a phototropic bending angle exceeding 180°toward the light source within 45 s.To showcase its practical potential,proof-of-concept photoactuated devices with flower-,hook-,and gripper-like and local-orientation processed strip-shaped structures were fabricated,which exhibited rapid and reversible light-triggered deformation.This study proposes a novel strategy for the development of intelligent polymeric materials that integrate light responsiveness,self-healing,and recyclability,thus holding great promise for applications in flexible electronics,smart actuators,and sustainable functional materials.
基金National Natural Science Foundation of China(Grant No.61903157)the Foundation of State Key Laboratory of Robotics(Grand No.2024-O08).
文摘Microrobotic systems are emerging as transformative technology for minimally invasive medicine,driven by innovations in actuation mechanisms,advanced fabrication paradigms,and multifunctional system integration.This comprehensive review analyzes the evolution of microrobotic technologies through three critical dimensions:(1)actuation modalities,including magnetic,optical,acoustic,chemical,and biological actuation,with a focus on the synergistic advantages of hybrid actuation strategies in complex internal physiological environments;(2)Fabrication methods cover technolo-gies such as photolithography,microinjection molding,self-assembly,and 3D printing,emphasizing innovative strategies involving multi-technology integration and collaborative manufacturing of bio/non-bio hybrid materials;(3)Internal phys-iological applications involve disease diagnosis,targeted drug delivery,minimally invasive surgery,tissue engineering,and cell manipulation,highlighting the broad prospects of microrobots in precision medicine.Despite remarkable progress,critical challenges remain,including low actuation efficiency,as seen in acoustic systems,limited biocompatibility,exem-plified by the toxicity of hydrogen peroxide in chemical actuation,delayed clinical translation,and other related challenges that must be addressed to advance the field.
基金The Central Government Guides Local Foundation for Science and Technology Development(Grant No.YDZJSX2024B004).
文摘The soft actuator is characterized by high safety,flexibility,and adaptability.It is capable of both active and passive defor-mations.This paper presents a discrete degree of freedom(DOF)method for soft actuators to reveal DOF characteristics.The method draws on the superposition mechanism of the deformation characteristics of the sarcomere in the skeletal muscles of living organisms.Firstly,the multi-DOF deformation characteristics of the soft actuator are discretized into superimposed combinations of single-DOF micro-units.Then,the soft actuator was determined to contain deformation characteristics such as extension-contraction,bending,and twisting.Eighteen types of micro-units with basic deforma-tion characteristics were obtained depending on the axis and orientation.Further,the mapping relationship between the combination of micro-units and the motion characteristics of the soft actuator based on the GF set theory was established.Finally,an active-passive DOF co-structured soft actuator(APCSA)was developed.The graphical approach analyzes the experimental results,and it can be concluded that active and passive DOFs can coexist in the composite deformation of the soft actuator.
基金Supported by the National High Technology Reserach and Development Program of China("863"program)(2005AA753031)the New Century Educational Talents Plan of Ministry of Education of China(NCET-05-0907)~~
文摘Plasma flow control is an active flow control technology that based on the plasma aerodynamic actuation. It can be used to enhance the aerodynamic characteristics of aircraft and propulsion systems. To study the phenomena occurring in plasma aerodynamic actuation and the mechanism of plasma flow control, the induced flow velocity of the plasma aerodynamic actuator is experimentally investigated under a variety of parameter conditions. The results indicate that plasma aerodynamic actuation accelerates the near surface air at velocities of a few meters per second, and there is an angle about 5° between the mainstream and the actuator wall and a spiral vortex is formed when the induced flow is moving along the wall. Besides, with the fixed frequency, the induced flow velocity increases linearly with the applied voltage, but it is insensitive to the frequency when the applied voltage is fixed. And the configuration is an effective factor for the performance of the plasma aerodynamic actuator.
基金completed in the Fluid Power and Tele-Robotics Research Laboratory at the University of Manitobathe supports of the Natural Sciences and Engineering Research Council(NSERC)of Canada+1 种基金China Scholarship Council(CSC)the National Natural Science Foundation of China(Nos.51275021 and 61327807)
文摘Electrohydrostatic actuator（EHA） is a type of power-by-wire actuator that is widely implemented in the aerospace industry for flight control, landing gears, thrust reversers, thrust vector control, and space robots. This paper presents the development and evaluation of positionbased impedance control（PBIC） for an EHA. Impedance control provides the actuator with compliance and facilitates the interaction with the environment. Most impedance control applications utilize electrical or valve-controlled hydraulic actuators, whereas this work realizes impedance control via a compact and efficient EHA. The structures of the EHA and PBIC are firstly introduced. A mathematical model of the actuation system is established, and values of its coefficients are identified by particle swarm optimization. This model facilitates the development of a position controller and the selection of target impedance parameters. A nonlinear proportional-integral position controller is developed for the EHA to achieve the accurate positioning requirement of PBIC. The controller compensates for the adverse effect of stiction, and a position accuracy of 0.08 mm is attained.Various experimental results are presented to verify the applicability of PBIC to the EHA. The compliance of the actuator is demonstrated in an impact test.
基金National Natural Science Foundation of China （50675009） International Science ＆ Technology Cooperation Program of China （2010DFA72540）
文摘The optional types of power source and actuator in the aircraft are more and more diverse due to fast development in more electric technology, which makes the combinations of different power sources and actuators become extremely complex in the architecture optimization process of airborne actuation system. The traditional ＂trial and error＂ method cannot satisfy the design demands. In this paper, firstly, the composition of more electric aircraft （MEA） flight control actuation system （FCAS） is introduced, and the possible architecture quantity is calculated. Secondly, the evaluation criteria of FCAS architecture with respect to safe reliability, weight and efficiency are proposed, and the evaluation criteria values are calculated in the case that each control surface adopts the same actuator configuration. Finally, the optimization results of MEA FCAS architecture are obtained by applying genetic algorithm （GA）. Compared to the traditional actuation system architecture, which only adopts servo valve controlled hydraulic actuators, the weight of the optimized more electric actuation system architecture can be reduced by 6%, and the efficiency can be improved by 30% based on the safe reliability requirements.
基金National Natural Science Foundation of China(50906100, 10972236)Foundation for the Author of National Excellent Doctoral Dissertation of PR China (201172)Postgraduate Technology Innovation Foundation of Air Force Engineering University(DX2010103)
文摘To discover the characteristic of separated flows and mechanism of plasma flow control on a highly loaded compressor cascade, numerical investigation is conducted. The simulation method is validated by oil flow visualization and pressure distribution. The loss coefficients, streamline patterns, and topology structure as well as vortex structure are analyzed. Results show that the numbers of singular points increase and three pairs of additional singular points of topology structure on solid surface generate with the increase of angle of attack, and the total pressure loss increases greatly. There are several principal vortices inside the cascade passage. The pressure side leg of horse-shoe vortex coexists within a specific region together with passage vortex, but finally merges into the latter. Corner vortex exists independently and does not evolve from the suction side leg of horse-shoe vortex. One pair of radial coupling-vortex exists near blade trailing edge and becomes the main part of backflow on the suction surface. Passage vortex interacts with the concentrated shedding vortex and they evolve into a large-scale vortex rotating in the direction opposite to passage vortex. The singular points and separation lines represent the basic separation feature of cascade passage. Plasma actuation has better effect at low freestream velocity, and the relative reductions of pitch-averaged total pressure loss coefficient with different actuation layouts of five and two pairs of electrodes are up to 30.8% and 26.7% while the angle of attack is 2~. Plasma actuation changes the local topology structure, but does not change the number relation of singular points. One pair of additional singular point of topology structure generates with plasma actuation and one more reattachment line appears, both of which break the separation line on the suction surface.
