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
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
As a kind of ionic artificial muscle material,Ionic Polymer-Metal Composites(IPMCs)have the advantages of a low drive current,light weight,and significant flexibility.IPMCs are widely used in the fields of biomedicine...As a kind of ionic artificial muscle material,Ionic Polymer-Metal Composites(IPMCs)have the advantages of a low drive current,light weight,and significant flexibility.IPMCs are widely used in the fields of biomedicine,soft robots,etc.However,the displacement and blocking force of the traditional sheet-type Nafion-IPMC need to be improved,and it has the limitation of unidirectional actuation.In this paper,a new type of short side chain Aquivion material is used as the polymer in the IPMC.The cylindrical IPMC is prepared by extrusion technology to improve its actuation performance and realize multi-degree-of-freedom motion.In comparison to the traditional Nafion-IPMC,the ion exchange capacity,specific capacitance,and conductivity of Aquivion-IPMC are improved by 28%,27%,and 32%,respectively,and the displacement and blocking force are improved by 57%and 25%,respectively.The cylindrical actuators can be deflected in eight directions.This indicates that Aquivion,as a polymer membrane for IPMC,holds significant application potential.By designing a cylindrical IPMC electrode distribution,the multi-degree-of-freedom deflection of IPMC can be realized.展开更多
To prepare a conductive polymer actuator with decent performance,a self-built experimental platform for the preparation of polypyrrole film is employed.One of the essential goals is to examine the mechanical character...To prepare a conductive polymer actuator with decent performance,a self-built experimental platform for the preparation of polypyrrole film is employed.One of the essential goals is to examine the mechanical characteristics of the actuator in the presence of various combinations of process parameters,combined with the orthogonal test method of"four factors and three levels".The bending and sensing characteristics of actuators of various sizes are methodically examined using a self-made bending polypyrrole actuator.The functional relationship between the bending displacement and the output voltage signal is established by studying the characteristics of the actuator sensor subjected to various degrees of bending.The experimental results reveal that the bending displacement of the actuator tip almost exhibits a linear variation as a function of length and width.When the voltage reaches 0.8 V,the bending speed of the actuator tends to be stable.Finally,the mechanical properties of the self-assembled polypyrrole actuator are verified by the design and fabrication of the microgripper.展开更多
The Electro–Hydrostatic Actuator(EHA)is applied to drive the control surface in flightcontrol system of more electric aircraft.In EHA,the Oil-Immersed Motor Pump(OMP)serves asthe core as a power assembly.However,the ...The Electro–Hydrostatic Actuator(EHA)is applied to drive the control surface in flightcontrol system of more electric aircraft.In EHA,the Oil-Immersed Motor Pump(OMP)serves asthe core as a power assembly.However,the compact integration of the OMP presents challenges inefficiently dissipating internal heat,leading to a performance degradation of the EHA due to ele-vated temperatures.Therefore,accurately modeling and predicting the internal thermal dynamicsof the OMP hold considerable significance for monitoring the operational condition of the EHA.In view of this,a modeling method considering cumulative thermal coupling was hereby proposed.Based on the proposed method,the thermal models of the motor and the pump were established,taking into account heat accumulation and transfer.Taking the leakage oil as the heat couplingpoint between the motor and the pump,the dynamic thermal coupling model of the OMP wasdeveloped,with the thermal characteristics of the oil considered.Additionally,the comparativeexperiments were conducted to illustrate the efficiency of the proposed model.The experimentalresults demonstrate that the proposed dynamic thermal coupling model accurately captured thethermal behavior of OMP,outperforming the static thermal parameter model.Overall,thisadvancement is crucial for effectively monitoring the health of EHA and ensuring flight safety.展开更多
Actuator faults can be critical in turbofan engines as they can lead to stall,surge,loss of thrust and failure of speed control.Thus,fault diagnosis of gas turbine actuators has attracted considerable attention,from b...Actuator faults can be critical in turbofan engines as they can lead to stall,surge,loss of thrust and failure of speed control.Thus,fault diagnosis of gas turbine actuators has attracted considerable attention,from both academia and industry.However,the extensive literature that exists on this topic does not address identifying the severity of actuator faults and focuses mainly on actuator fault detection and isolation.In addition,previous studies of actuator fault identification have not dealt with multiple concurrent faults in real time,especially when these are accompanied by sudden failures under dynamic conditions.This study develops component-level models for fault identification in four typical actuators used in high-bypass ratio turbofan engines under both dynamic and steady-state conditions and these are then integrated with the engine performance model developed by the authors.The research results reported here present a novel method of quantifying actuator faults using dynamic effect compensation.The maximum error for each actuator is less than0.06%and 0.07%,with average computational time of less than 0.0058 s and 0.0086 s for steady-state and transient cases,respectively.These results confirm that the proposed method can accurately and efficiently identify concurrent actuator fault for an engine operating under either transient or steady-state conditions,even in the case of a sudden malfunction.The research results emonstrate the potential benefit to emergency response capabilities by introducing this method of monitoring the health of aero engines.展开更多
Piezoelectric active vibration control holds paramount importance in space structures.An embedded piezoelectric actuator with a sandwich configuration is proposed,which enhances control accuracy by integrating various...Piezoelectric active vibration control holds paramount importance in space structures.An embedded piezoelectric actuator with a sandwich configuration is proposed,which enhances control accuracy by integrating various components.Firstly,the electromechanical coupling characteristics of the actuator are revealed,and the model is established.Secondly,the equivalent model of a cylindrical cantilever beam is investigated as the object,and the feasibility of the vibration control of the actuator is verified by simulation.Finally,the prototype comprised of two actuators,which respectively use the proposed embedded actuators for producing the vibration and suppressing the vibration,is developed,and the measurement system is constructed.Experimental results demonstrate the excellent control efficiency in two orthogonal directions,achieving a minimum vibration amplitude control of 0.00102 mm and a maximum vibration control of-42.74 d B.The integrated structure offers fast response,lightness,adaptability,and high control efficiency,which is conducive to enhancing the vibration control.展开更多
This paper presents an untethered pneumatic soft robot which can crawl both in horizontal and vertical pipes with different sizes and cross sections.This robot uses modular origami inspired soft-rigid hybrid actuator ...This paper presents an untethered pneumatic soft robot which can crawl both in horizontal and vertical pipes with different sizes and cross sections.This robot uses modular origami inspired soft-rigid hybrid actuator to produce telescoping and anchoring movements powered by vacuum pressure.The introduction of grooves to valley crease significantly lowers the full contraction vacuum pressure and improves the response,allowing the system can be driven by an onboard micro vacuum pump,enabling the possibility of miniaturization,integration,and untethered operation of the robot.A series of crawling experiments in pipes with different sizes and cross sections constructed by acrylic are conducted to validate the crawling performance of the robot.Within square cross-section pipes,the robot can achieve a velocity of 9.4 mm/s in horizontal crawling and 7.7 mm/s in vertical upward crawling.For horizontal crawling in circular pipes,it can reach a velocity of 8.0 mm/s.When fully charged,the robot can crawl for 40 min with a mileage of 16.649 m,which is sufficient for most drainage and industrial pipelines detection tasks.The robot demonstrates excellent endurance and speed performance that exceed most existing untethered soft pipe crawling robots.展开更多
Tendon-driven robots have distinct advantages in high-dynamic performance motion and high-degree-of-freedom manipulation.However,these robots face challenges related to control complexity,intricate tendon drive paths,...Tendon-driven robots have distinct advantages in high-dynamic performance motion and high-degree-of-freedom manipulation.However,these robots face challenges related to control complexity,intricate tendon drive paths,and tendon slackness.In this study,the authors present a novel modular tendon-driven actuator design that integrates a series elastic element.The actuator incorporates a unique magnetic position sensing technology that enables observation of the length and tension of the tendon and features an exceptionally compact design.The modular architecture of the tendon-driven actuator addresses the complexity of tendon drive paths,while the tension observation functionality mitigates slackness issues.The design and modeling of the actuator are described in this paper,and a series of tests are conducted to validate the simulation model and to test the performance of the proposed actuator.The model can be used for training robot control neural networks based on simulation,thereby overcoming the challenges associated with controlling tendon-driven robots.展开更多
MXene(Ti3C2Tx)is known for its excellent hydrophilicity,electrical conductivity,and dispersibility.It is a promising candidate for the fabrication of moisture-responsive actuators due to the strong interaction between...MXene(Ti3C2Tx)is known for its excellent hydrophilicity,electrical conductivity,and dispersibility.It is a promising candidate for the fabrication of moisture-responsive actuators due to the strong interaction between MXene sheets and water molecules.Inspired by natural organisms,a variety of moisture-actuated soft robots have been successfully developed through the systematic integration of MXene-based actuators.This minireview summarizes recent advances in the preparation and applications of MXene-based moisture-responsive actuators.The hydrophilic properties of MXene,along with design principles,working mechanisms,current progress,and applications of MXenebased actuators,are discussed.The future prospects and developmental directions of MXene-based moisture-responsive actuators are put forward,providing novel insights for their further advancement in the realm of automatable smart devices.展开更多
Piezoelectric actuators are widely utilized in positioning systems to realize nano-scale resolution. However, the backward motion always generates for some piezoelectric actuators, which reduces the working efficiency...Piezoelectric actuators are widely utilized in positioning systems to realize nano-scale resolution. However, the backward motion always generates for some piezoelectric actuators, which reduces the working efficiency. Bionic motions have already been employed in the field of piezoelectric actuators to realize better performance. By imitating the movement form of seals, seal type piezoelectric actuator is capable to realize large operating strokes easily. Nevertheless, the conventional seal type piezoelectric actuator has a complicated structure and control system, which limits further applications. Hence, an improved bionic piezoelectric actuator is proposed to realize a long motion stroke and eliminate backward movement with a simplified structure and control method in this study. The composition and motion principle of the designed actuator are discussed, and the performance is investigated with simulations and experiments. Results confirm that the presented actuator effectively realizes the linear movement that has a large working stroke stably without backward motion. The smallest stepping displacement ΔL is 0.2 μm under 1 Hz and 50 V. The largest motion speed is 900 μm/s with 900 Hz and 120 V. The largest vertical and horizontal load are 250 g and 12 g, respectively. This work shows that the improved bionic piezoelectric actuator is feasible for eliminating backward motion and has a great working ability.展开更多
Chassis-by-wire technology has gained significant attention,with the scope of chassis domain control expanding from traditional two-dimensional plane motion control to encompass three-dimensional space motion control....Chassis-by-wire technology has gained significant attention,with the scope of chassis domain control expanding from traditional two-dimensional plane motion control to encompass three-dimensional space motion control.Modern chassis-by-wire systems manage an increasing number of heterogeneous chassis execution systems,including distributed drive,all-wheel drive(AWD),brake-by-wire(BBW),steer-by-wire(SBW),rear-wheel steering(RWS),active stabilizer bar(ASB)and active suspension system(ASS),greatly enhancing the controllable degrees of freedom compared to conventional chassis configurations.To advance research in chassis domain control,it is essential to understand how these heterogeneous execution systems influence vehicle dynamics.This paper focuses on the modeling and analysis of the lateral,longitudinal,and vertical chassis control and execution systems,-as well as their impact on vehicle lateral motion.Using a vehicle simulation platform,both the vehicle dynamics model and the individual dynamics models of each execution system were developed to analyze the influence of these systems on lateral dynamics.Additionally,a hierarchical control architecture was designed to control the vehicle’s lateral stability.The effectiveness of the proposed control scheme was demonstrated and validated through hardware-in-the-loop(HIL)tests and real-world vehicle testing.展开更多
Soft underwater swimming robots driven by smart materials show unique advantages in ocean exploration,such as low noise,high flexibility and good environmental interaction ability.The dielectric elastomer(DE),as a new...Soft underwater swimming robots driven by smart materials show unique advantages in ocean exploration,such as low noise,high flexibility and good environmental interaction ability.The dielectric elastomer(DE),as a new kind of soft intelligent material,has the characteristics of a low elastic modulus,large deformation range,high energy density and fast response speed.DE actuator(DEA)drive systems use the deformation characteristics of dielectric materials to drive the mechanical system,which has become a research hotspot in the field of soft robots.In this paper,a tubular actuator based on DEs is designed and its performance is studied.Firstly,the structure and driving process of a DEA are described,and a tubular DEA is designed.Studying the elongation ratio of the DEA pre-stretching shows that when the axial elongation ratio is 3 times and the circumferential elongation ratio is 4 times,the maximum deformation effect can be obtained under voltage excitation.At a voltage of 6.0 k V,a single pipe section DEA achieves a bending angle of 25.9°and a driving force of 73.8 m N.Secondly,the effect of the DEA series on the bending angle and response characteristics is studied.The experimental results show that the maximum bending angle of the three joint actuators in series can reach 59.3°under6.0 k V voltage,which significantly improves the overall bending performance.In addition,the truncation frequency of the drive module after the series is increased to 0.62 Hz,showing better frequency response capability.The excellent performance of the pipe joint actuator in its bending angle,response characteristic and driving force is verified.展开更多
Stimulus-responsive actuators are novel functional devices capable of sensing external stimuli and ex-hibiting specific deformation responses.MXene,owing to its unique 2D structure and efficient energy conversion effi...Stimulus-responsive actuators are novel functional devices capable of sensing external stimuli and ex-hibiting specific deformation responses.MXene,owing to its unique 2D structure and efficient energy conversion efficiency,has bridged the gap in traditional devices and shown great potential for multiple stimulus-responsive actuators.However,the drawbacks of pure MXene films,including susceptibility to oxidation and vulnerability to shear stress,hinder their applications.Through composite modification and structural design strategies,a three-layer structured MXene-carbon nanotubes hybrid film(tHCM)is fabri-cated,exhibiting a tensile strength and fracture strain of 153.8 MPa and 4.65%,respectively,representing improvements of 598.4%and 226.8%compared to the initial film.Meanwhile,the film maintains excel-lent stability demonstrating the enhancing effects of hydrogen bonds and densely packed structure.The hybrid films demonstrate unique and facile welding features due to splicing properties,enabling the for-mation of complex configurations.In terms of electro-/photo-thermal conversion performance,the hybrid film can reach a reasonably high temperature of 250℃at low voltage(2.5 V)and 110.6℃under 150 mW cm^(-2) infrared light.Leveraging the thermal expansion mismatch between tHCM and thermoplastic films,an integrated,flexible,and weldable actuator with unique electro/photo-response is developed,and vari-ous biomimetic driving applications,particularly,the light-mediated hierarchical transmission and precise motion along predetermined trajectory are realized.This work not only provides an effective strategy for modifying MXene composite films but also advances the design of novel actuators,offering broad appli-cation prospects in fields such as stimulus-responsive actuated robots and cargo transportation.展开更多
By combining with an improved model on engraving process,a two-phase flow interior ballistic model has been proposed to accurately predict the flow and energy conversion behaviors of pyrotechnic actuators.Using comput...By combining with an improved model on engraving process,a two-phase flow interior ballistic model has been proposed to accurately predict the flow and energy conversion behaviors of pyrotechnic actuators.Using computational fluid dynamics(CFD),the two-phase flow and piston engraving characteristics of a pyrotechnic actuator are investigated.Initially,the current model was utilized to examine the intricate,multi-dimensional flow,and energy conversion characteristics of the propellant grains and combustion gas within the pyrotechnic actuator chamber.It was discovered that the combustion gas on the wall's constant transition from potential to kinetic energy,along with the combined effect of the propellant motion,are what create the pressure oscillation within the chamber.Additionally,a numerical analysis was conducted to determine the impact of various parameters on the pressure oscillation and piston motion,including pyrotechnic charge,pyrotechnic particle size,and chamber structural dimension.The findings show that decreasing the pyrotechnic charge will lower the terminal velocity,while increasing and decreasing the pyrotechnic particle size will reduce the pressure oscillation in the chamber.The pyrotechnic particle size has minimal bearing on the terminal velocity.The results of this investigation offer a trustworthy forecasting instrument for comprehending and creating pyrotechnic actuator designs.展开更多
Hydraulic-electric systems are widely utilized in various applications.However,over time,these systems may encounter random faults such as loose cables,ambient environmental noise,or sensor aging,leading to inaccurate...Hydraulic-electric systems are widely utilized in various applications.However,over time,these systems may encounter random faults such as loose cables,ambient environmental noise,or sensor aging,leading to inaccurate sensor readings.These faults may result in system instability or compromise safety.In this paper,we propose a fault compensation control system to mitigate the effects of sensor faults and ensure system safety.Specifically,we utilize the pressure sensor within the system to implement the control process and evaluate performance based on the piston position.First,we develop a mathematical model to identify optimal parameters for the fault estimation model based on the Lyapunov stability principle.Next,we design an unknown input observer that estimates the state vector and detects pressure sensor faults using a linear matrix inequality optimization algorithm.The estimated pressure faults are incorporated into the fault compensation control system to counteract their effects via a fault residual coefficient.The discrepancy between the feedback state and the estimated state determines this coefficient.We assess the piston position’s performance through pressure control to evaluate the proposed model’s effectiveness.Finally,the system simulation results are analyzed to validate the efficiency of the proposed model.When a pressure sensor fault occurs,the proposed approach effectively minimizes position control errors,enhancing overall system stability.When a pressure sensor fault occurs,the proposed model compensates for the fault to mitigate the impact of pressure problem,thereby enhancing the position control quality of the EHA system.The fault compensation method ensures over 90%system performance,with its effectiveness becoming more evident under pressure sensor faults.展开更多
Developing flexible actuators with high transport efficiency is of great significance for the emerging applications of micro-robots in various industrial and biomedical environments.Despite recent advancements have en...Developing flexible actuators with high transport efficiency is of great significance for the emerging applications of micro-robots in various industrial and biomedical environments.Despite recent advancements have enabled soft materials to achieve complex functionalities unattainable by traditional rigid robots,achieving high-speed transport performance for solid particles remains a significant challenge.Magnetic materials,as an integral component of scientific applications,have demonstrated substantial potential in areas such as biological imaging,catalysis,and energy storage.Inspired by the flexible,soft,and elastic microciliary structures of many organisms,a soft actuator decorated with magnetic microcilia was reported.This soft magnetic microciliary actuator achieves high speed(50 mm s^(-1))transport of solid microspheres by means of magnetic field regulate their surface morphology.Overcoming the limitations of prior studies in which the speed of motion was constrained to a few millimeters per second due to hysteresis effects,this work represents a significant advancement in the emerging field of biomimetic flexible actuators and holds promise in various applications.展开更多
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financial support from the National Natural Science Foundation of China(Grant No.U1637101)The Research Fund of State Key Laboratory of Mechanics and Control for Aerospace Structures(1005-ZAG23011).
文摘As a kind of ionic artificial muscle material,Ionic Polymer-Metal Composites(IPMCs)have the advantages of a low drive current,light weight,and significant flexibility.IPMCs are widely used in the fields of biomedicine,soft robots,etc.However,the displacement and blocking force of the traditional sheet-type Nafion-IPMC need to be improved,and it has the limitation of unidirectional actuation.In this paper,a new type of short side chain Aquivion material is used as the polymer in the IPMC.The cylindrical IPMC is prepared by extrusion technology to improve its actuation performance and realize multi-degree-of-freedom motion.In comparison to the traditional Nafion-IPMC,the ion exchange capacity,specific capacitance,and conductivity of Aquivion-IPMC are improved by 28%,27%,and 32%,respectively,and the displacement and blocking force are improved by 57%and 25%,respectively.The cylindrical actuators can be deflected in eight directions.This indicates that Aquivion,as a polymer membrane for IPMC,holds significant application potential.By designing a cylindrical IPMC electrode distribution,the multi-degree-of-freedom deflection of IPMC can be realized.
基金Funded by the National Natural Science Foundation of Hunan Province,Chinal(No.2021JJ60012)。
文摘To prepare a conductive polymer actuator with decent performance,a self-built experimental platform for the preparation of polypyrrole film is employed.One of the essential goals is to examine the mechanical characteristics of the actuator in the presence of various combinations of process parameters,combined with the orthogonal test method of"four factors and three levels".The bending and sensing characteristics of actuators of various sizes are methodically examined using a self-made bending polypyrrole actuator.The functional relationship between the bending displacement and the output voltage signal is established by studying the characteristics of the actuator sensor subjected to various degrees of bending.The experimental results reveal that the bending displacement of the actuator tip almost exhibits a linear variation as a function of length and width.When the voltage reaches 0.8 V,the bending speed of the actuator tends to be stable.Finally,the mechanical properties of the self-assembled polypyrrole actuator are verified by the design and fabrication of the microgripper.
基金supported by the National Key R&D Program of China(No.2021YFB2011300)the National Natural Science Foundation of China(Nos.52275044,U2233212)。
文摘The Electro–Hydrostatic Actuator(EHA)is applied to drive the control surface in flightcontrol system of more electric aircraft.In EHA,the Oil-Immersed Motor Pump(OMP)serves asthe core as a power assembly.However,the compact integration of the OMP presents challenges inefficiently dissipating internal heat,leading to a performance degradation of the EHA due to ele-vated temperatures.Therefore,accurately modeling and predicting the internal thermal dynamicsof the OMP hold considerable significance for monitoring the operational condition of the EHA.In view of this,a modeling method considering cumulative thermal coupling was hereby proposed.Based on the proposed method,the thermal models of the motor and the pump were established,taking into account heat accumulation and transfer.Taking the leakage oil as the heat couplingpoint between the motor and the pump,the dynamic thermal coupling model of the OMP wasdeveloped,with the thermal characteristics of the oil considered.Additionally,the comparativeexperiments were conducted to illustrate the efficiency of the proposed model.The experimentalresults demonstrate that the proposed dynamic thermal coupling model accurately captured thethermal behavior of OMP,outperforming the static thermal parameter model.Overall,thisadvancement is crucial for effectively monitoring the health of EHA and ensuring flight safety.
基金support by the National Natural Science Foundation of China(Grant No.52402520)。
文摘Actuator faults can be critical in turbofan engines as they can lead to stall,surge,loss of thrust and failure of speed control.Thus,fault diagnosis of gas turbine actuators has attracted considerable attention,from both academia and industry.However,the extensive literature that exists on this topic does not address identifying the severity of actuator faults and focuses mainly on actuator fault detection and isolation.In addition,previous studies of actuator fault identification have not dealt with multiple concurrent faults in real time,especially when these are accompanied by sudden failures under dynamic conditions.This study develops component-level models for fault identification in four typical actuators used in high-bypass ratio turbofan engines under both dynamic and steady-state conditions and these are then integrated with the engine performance model developed by the authors.The research results reported here present a novel method of quantifying actuator faults using dynamic effect compensation.The maximum error for each actuator is less than0.06%and 0.07%,with average computational time of less than 0.0058 s and 0.0086 s for steady-state and transient cases,respectively.These results confirm that the proposed method can accurately and efficiently identify concurrent actuator fault for an engine operating under either transient or steady-state conditions,even in the case of a sudden malfunction.The research results emonstrate the potential benefit to emergency response capabilities by introducing this method of monitoring the health of aero engines.
基金supported by the National Natural Science Foundation of China(Nos.52275022,52175015 and U2037603)the Natural Science Foundation of Jiangsu Province,China(Nos.BK20222011 and BK20230093)the State Key Laboratory of Mechanics and Control for Aerospace Structures,China(No.MCAS-S-0223G01)。
文摘Piezoelectric active vibration control holds paramount importance in space structures.An embedded piezoelectric actuator with a sandwich configuration is proposed,which enhances control accuracy by integrating various components.Firstly,the electromechanical coupling characteristics of the actuator are revealed,and the model is established.Secondly,the equivalent model of a cylindrical cantilever beam is investigated as the object,and the feasibility of the vibration control of the actuator is verified by simulation.Finally,the prototype comprised of two actuators,which respectively use the proposed embedded actuators for producing the vibration and suppressing the vibration,is developed,and the measurement system is constructed.Experimental results demonstrate the excellent control efficiency in two orthogonal directions,achieving a minimum vibration amplitude control of 0.00102 mm and a maximum vibration control of-42.74 d B.The integrated structure offers fast response,lightness,adaptability,and high control efficiency,which is conducive to enhancing the vibration control.
基金supported by National Natural Science Foundation of China under Grant no.52475067.
文摘This paper presents an untethered pneumatic soft robot which can crawl both in horizontal and vertical pipes with different sizes and cross sections.This robot uses modular origami inspired soft-rigid hybrid actuator to produce telescoping and anchoring movements powered by vacuum pressure.The introduction of grooves to valley crease significantly lowers the full contraction vacuum pressure and improves the response,allowing the system can be driven by an onboard micro vacuum pump,enabling the possibility of miniaturization,integration,and untethered operation of the robot.A series of crawling experiments in pipes with different sizes and cross sections constructed by acrylic are conducted to validate the crawling performance of the robot.Within square cross-section pipes,the robot can achieve a velocity of 9.4 mm/s in horizontal crawling and 7.7 mm/s in vertical upward crawling.For horizontal crawling in circular pipes,it can reach a velocity of 8.0 mm/s.When fully charged,the robot can crawl for 40 min with a mileage of 16.649 m,which is sufficient for most drainage and industrial pipelines detection tasks.The robot demonstrates excellent endurance and speed performance that exceed most existing untethered soft pipe crawling robots.
基金supported in part by the National Key R&D Program of China under Grant 2024YFB4707900the National Natural Science Foundation of China under Grant 91948302 and Grant 52021003.
文摘Tendon-driven robots have distinct advantages in high-dynamic performance motion and high-degree-of-freedom manipulation.However,these robots face challenges related to control complexity,intricate tendon drive paths,and tendon slackness.In this study,the authors present a novel modular tendon-driven actuator design that integrates a series elastic element.The actuator incorporates a unique magnetic position sensing technology that enables observation of the length and tension of the tendon and features an exceptionally compact design.The modular architecture of the tendon-driven actuator addresses the complexity of tendon drive paths,while the tension observation functionality mitigates slackness issues.The design and modeling of the actuator are described in this paper,and a series of tests are conducted to validate the simulation model and to test the performance of the proposed actuator.The model can be used for training robot control neural networks based on simulation,thereby overcoming the challenges associated with controlling tendon-driven robots.
基金supported by the National Key R&D Program of China(2023YFB3812800)the Joint Fund for Regional Innovation and Development of National Natural Science Foundation China(No.U24A2078)+3 种基金the National Natural Science Foundation of China(Nos.52173181,51973155,52205599)Tianjin Science Fund for Distinguished Young Scholars(22JCJQJC00060)the Youth Science Fund Program of Shanxi Province(202203021212203)China Postdoctoral Science Foundation(No.2024M752361).
文摘MXene(Ti3C2Tx)is known for its excellent hydrophilicity,electrical conductivity,and dispersibility.It is a promising candidate for the fabrication of moisture-responsive actuators due to the strong interaction between MXene sheets and water molecules.Inspired by natural organisms,a variety of moisture-actuated soft robots have been successfully developed through the systematic integration of MXene-based actuators.This minireview summarizes recent advances in the preparation and applications of MXene-based moisture-responsive actuators.The hydrophilic properties of MXene,along with design principles,working mechanisms,current progress,and applications of MXenebased actuators,are discussed.The future prospects and developmental directions of MXene-based moisture-responsive actuators are put forward,providing novel insights for their further advancement in the realm of automatable smart devices.
基金supported by The Key Science and Technology Plan Project of Jinhua City,China:2023-3-084,2023-2-011Zhejiang Provincial"Revealing the list and taking command"Project of China KYH06Y22349Open Fund Project of Key Laboratory of CNC Equipment reliability,Ministry of Education JLU-cncr-202407.
文摘Piezoelectric actuators are widely utilized in positioning systems to realize nano-scale resolution. However, the backward motion always generates for some piezoelectric actuators, which reduces the working efficiency. Bionic motions have already been employed in the field of piezoelectric actuators to realize better performance. By imitating the movement form of seals, seal type piezoelectric actuator is capable to realize large operating strokes easily. Nevertheless, the conventional seal type piezoelectric actuator has a complicated structure and control system, which limits further applications. Hence, an improved bionic piezoelectric actuator is proposed to realize a long motion stroke and eliminate backward movement with a simplified structure and control method in this study. The composition and motion principle of the designed actuator are discussed, and the performance is investigated with simulations and experiments. Results confirm that the presented actuator effectively realizes the linear movement that has a large working stroke stably without backward motion. The smallest stepping displacement ΔL is 0.2 μm under 1 Hz and 50 V. The largest motion speed is 900 μm/s with 900 Hz and 120 V. The largest vertical and horizontal load are 250 g and 12 g, respectively. This work shows that the improved bionic piezoelectric actuator is feasible for eliminating backward motion and has a great working ability.
基金Supported by National Nature Science Foundation of China(Grant Nos.52325212,52372394)National Key Research and Development Program of China(Grant Nos.2022YFE0117100,2021YFB2501201)+1 种基金Industry-University-Research Innovation Fund for Chinese Universities(Grand No.2024HT010)Fundamental Research Funds for the Central Universities.
文摘Chassis-by-wire technology has gained significant attention,with the scope of chassis domain control expanding from traditional two-dimensional plane motion control to encompass three-dimensional space motion control.Modern chassis-by-wire systems manage an increasing number of heterogeneous chassis execution systems,including distributed drive,all-wheel drive(AWD),brake-by-wire(BBW),steer-by-wire(SBW),rear-wheel steering(RWS),active stabilizer bar(ASB)and active suspension system(ASS),greatly enhancing the controllable degrees of freedom compared to conventional chassis configurations.To advance research in chassis domain control,it is essential to understand how these heterogeneous execution systems influence vehicle dynamics.This paper focuses on the modeling and analysis of the lateral,longitudinal,and vertical chassis control and execution systems,-as well as their impact on vehicle lateral motion.Using a vehicle simulation platform,both the vehicle dynamics model and the individual dynamics models of each execution system were developed to analyze the influence of these systems on lateral dynamics.Additionally,a hierarchical control architecture was designed to control the vehicle’s lateral stability.The effectiveness of the proposed control scheme was demonstrated and validated through hardware-in-the-loop(HIL)tests and real-world vehicle testing.
基金Project supported by the Science and Technology Research Project of Henan Province in China(Grant No.222102220022)。
文摘Soft underwater swimming robots driven by smart materials show unique advantages in ocean exploration,such as low noise,high flexibility and good environmental interaction ability.The dielectric elastomer(DE),as a new kind of soft intelligent material,has the characteristics of a low elastic modulus,large deformation range,high energy density and fast response speed.DE actuator(DEA)drive systems use the deformation characteristics of dielectric materials to drive the mechanical system,which has become a research hotspot in the field of soft robots.In this paper,a tubular actuator based on DEs is designed and its performance is studied.Firstly,the structure and driving process of a DEA are described,and a tubular DEA is designed.Studying the elongation ratio of the DEA pre-stretching shows that when the axial elongation ratio is 3 times and the circumferential elongation ratio is 4 times,the maximum deformation effect can be obtained under voltage excitation.At a voltage of 6.0 k V,a single pipe section DEA achieves a bending angle of 25.9°and a driving force of 73.8 m N.Secondly,the effect of the DEA series on the bending angle and response characteristics is studied.The experimental results show that the maximum bending angle of the three joint actuators in series can reach 59.3°under6.0 k V voltage,which significantly improves the overall bending performance.In addition,the truncation frequency of the drive module after the series is increased to 0.62 Hz,showing better frequency response capability.The excellent performance of the pipe joint actuator in its bending angle,response characteristic and driving force is verified.
基金support provided by the National Natural Science Foundation of China(No.52002324)the Hong Kong Scholars Program(Nos.XJ2021073 and PolyU YZ4V)the Research Grants Council of Hong Kong GRF(No.15303123).
文摘Stimulus-responsive actuators are novel functional devices capable of sensing external stimuli and ex-hibiting specific deformation responses.MXene,owing to its unique 2D structure and efficient energy conversion efficiency,has bridged the gap in traditional devices and shown great potential for multiple stimulus-responsive actuators.However,the drawbacks of pure MXene films,including susceptibility to oxidation and vulnerability to shear stress,hinder their applications.Through composite modification and structural design strategies,a three-layer structured MXene-carbon nanotubes hybrid film(tHCM)is fabri-cated,exhibiting a tensile strength and fracture strain of 153.8 MPa and 4.65%,respectively,representing improvements of 598.4%and 226.8%compared to the initial film.Meanwhile,the film maintains excel-lent stability demonstrating the enhancing effects of hydrogen bonds and densely packed structure.The hybrid films demonstrate unique and facile welding features due to splicing properties,enabling the for-mation of complex configurations.In terms of electro-/photo-thermal conversion performance,the hybrid film can reach a reasonably high temperature of 250℃at low voltage(2.5 V)and 110.6℃under 150 mW cm^(-2) infrared light.Leveraging the thermal expansion mismatch between tHCM and thermoplastic films,an integrated,flexible,and weldable actuator with unique electro/photo-response is developed,and vari-ous biomimetic driving applications,particularly,the light-mediated hierarchical transmission and precise motion along predetermined trajectory are realized.This work not only provides an effective strategy for modifying MXene composite films but also advances the design of novel actuators,offering broad appli-cation prospects in fields such as stimulus-responsive actuated robots and cargo transportation.
基金supported by the National Natural Science Foundation of China(Grant No.11972194).
文摘By combining with an improved model on engraving process,a two-phase flow interior ballistic model has been proposed to accurately predict the flow and energy conversion behaviors of pyrotechnic actuators.Using computational fluid dynamics(CFD),the two-phase flow and piston engraving characteristics of a pyrotechnic actuator are investigated.Initially,the current model was utilized to examine the intricate,multi-dimensional flow,and energy conversion characteristics of the propellant grains and combustion gas within the pyrotechnic actuator chamber.It was discovered that the combustion gas on the wall's constant transition from potential to kinetic energy,along with the combined effect of the propellant motion,are what create the pressure oscillation within the chamber.Additionally,a numerical analysis was conducted to determine the impact of various parameters on the pressure oscillation and piston motion,including pyrotechnic charge,pyrotechnic particle size,and chamber structural dimension.The findings show that decreasing the pyrotechnic charge will lower the terminal velocity,while increasing and decreasing the pyrotechnic particle size will reduce the pressure oscillation in the chamber.The pyrotechnic particle size has minimal bearing on the terminal velocity.The results of this investigation offer a trustworthy forecasting instrument for comprehending and creating pyrotechnic actuator designs.
基金supported by Nguyen Tat Thanh University,Ho Chi Minh City,Vietnam,provided with the facilities required to carry out this work.
文摘Hydraulic-electric systems are widely utilized in various applications.However,over time,these systems may encounter random faults such as loose cables,ambient environmental noise,or sensor aging,leading to inaccurate sensor readings.These faults may result in system instability or compromise safety.In this paper,we propose a fault compensation control system to mitigate the effects of sensor faults and ensure system safety.Specifically,we utilize the pressure sensor within the system to implement the control process and evaluate performance based on the piston position.First,we develop a mathematical model to identify optimal parameters for the fault estimation model based on the Lyapunov stability principle.Next,we design an unknown input observer that estimates the state vector and detects pressure sensor faults using a linear matrix inequality optimization algorithm.The estimated pressure faults are incorporated into the fault compensation control system to counteract their effects via a fault residual coefficient.The discrepancy between the feedback state and the estimated state determines this coefficient.We assess the piston position’s performance through pressure control to evaluate the proposed model’s effectiveness.Finally,the system simulation results are analyzed to validate the efficiency of the proposed model.When a pressure sensor fault occurs,the proposed approach effectively minimizes position control errors,enhancing overall system stability.When a pressure sensor fault occurs,the proposed model compensates for the fault to mitigate the impact of pressure problem,thereby enhancing the position control quality of the EHA system.The fault compensation method ensures over 90%system performance,with its effectiveness becoming more evident under pressure sensor faults.
基金financially supported by the National Natural Science Foundation of China(Nos.22105014 and 52472293)the China Postdoctoral Science Foundation(Nos.2020M680296 and 2022T150035)+3 种基金the High-level Talent Project of Shenyang Ligong University(Nos.1010147001302)the Special fund of Basic Scientific Research Expenses for Undergraduate Universities in Liaoning Province(Nos.LJ212410144077 and LJ212410144072)Beijing Young Talent Support Program,the 111 Projectthe Fundamental Research Funds for the Central Universities
文摘Developing flexible actuators with high transport efficiency is of great significance for the emerging applications of micro-robots in various industrial and biomedical environments.Despite recent advancements have enabled soft materials to achieve complex functionalities unattainable by traditional rigid robots,achieving high-speed transport performance for solid particles remains a significant challenge.Magnetic materials,as an integral component of scientific applications,have demonstrated substantial potential in areas such as biological imaging,catalysis,and energy storage.Inspired by the flexible,soft,and elastic microciliary structures of many organisms,a soft actuator decorated with magnetic microcilia was reported.This soft magnetic microciliary actuator achieves high speed(50 mm s^(-1))transport of solid microspheres by means of magnetic field regulate their surface morphology.Overcoming the limitations of prior studies in which the speed of motion was constrained to a few millimeters per second due to hysteresis effects,this work represents a significant advancement in the emerging field of biomimetic flexible actuators and holds promise in various applications.
