The disadvantages caused by the swing of a fish body were analyzed. The coordinate system of a two-joint robot fish was built. The hydrodynamic analysis of robot fish was developed. The dynamic simulation of a two-joi...The disadvantages caused by the swing of a fish body were analyzed. The coordinate system of a two-joint robot fish was built. The hydrodynamic analysis of robot fish was developed. The dynamic simulation of a two-joint robot fish was carried out with the ADAMS software. The relationship between the swing of fish body and the mass distribution of robot fish, the relationship between the swing of fish body and the swing frequency of tail, were gained. The impact of the swing of fish body on the kinematic parameters of tail fin was analyzed. Three methods to restrain the swing of fish body were presented and discussed.展开更多
This paper presents a study on bioinspired closed-loop Central Pattern Generator(CPG)based control of a robot fish for obstacle avoidance and direction tracking.The biomimetic robot fish is made of a rigid head with a...This paper presents a study on bioinspired closed-loop Central Pattern Generator(CPG)based control of a robot fish for obstacle avoidance and direction tracking.The biomimetic robot fish is made of a rigid head with a pair of pectoral fins,a wire-driven active body covered with soft skin,and a compliant tail.The CPG model consists of four input parameters:the flapping amplitude,the flapping angular velocity,the flapping offset,and the time ratio between the beat phase and the restore phase in flapping.The robot fish is equipped with three infrared sensors mounted on the left,front and right of the robot fish,as well as an inertial measurement unit,from which the surrounding obstacles and moving direction can be sensed.Based on these sensor signals,the closed-loop CPG-based control can drive the robot fish to avoid obstacles and to track designated directions.Four sets of experiments are presented,including avoiding a static obstacle,avoiding a moving obstacle,tracking a designated direction and tracking a designated direction with an obstacle in the path.The experiment results indicated that the presented control strategy worked well and the robot fish can accomplish the obstacle avoidance and direction tracking effectively.展开更多
As a combination of bio-mechanism and engineering technology, robot fish has become a multidisci- plinary research that mainly involves both hydrodynamics-based control and actuation technology. This paper presents a ...As a combination of bio-mechanism and engineering technology, robot fish has become a multidisci- plinary research that mainly involves both hydrodynamics-based control and actuation technology. This paper presents a simplified propulsive model for carangiform propulsion, which is a swimming mode suitable for high speed and high efficiency. The carangiform motion is modeled as an N-joint nscillating mechanism that is composed of two basic components： the streamlined fish body represented by a planar spline curve and its hmate caudal tail by an oscillating foil. The speed of fish＇s straight swimming is adjusted by modulating the joint＇s oscillating frequency, and its orientation is tuned by different joint＇s deflection. The results from actual experiment showed that the proposed simplified propulsive model could be a viable eandidate for application in aquatic： swimming vehicles.展开更多
This paper concerns with 3-D locomotion control methods for a biomimetic robot fish. The system architecture of the fish is firstly presented based on a physical model of carangiform fish. The robot fish has a flexibl...This paper concerns with 3-D locomotion control methods for a biomimetic robot fish. The system architecture of the fish is firstly presented based on a physical model of carangiform fish. The robot fish has a flexible body, a rigid caudal fin and a pair of pectoral fins, driven by several servomotors. The motion control of the robot fish are then divided into speed control, orientation control, submerge control and transient motion control, corresponding algorithms are detailed respectively. Finally, experiments and analyses on a 4-link, radio-controlled robot fish prototype with 3-D locomotion show its good performance.展开更多
A mechanical design method of mbet fish is introduced in this paper. Based on this method, an autonomous 3-Dimension （3D） locomotion mbet fish with two pectoral fins and a caudal fin is developed. The pectoral fin m...A mechanical design method of mbet fish is introduced in this paper. Based on this method, an autonomous 3-Dimension （3D） locomotion mbet fish with two pectoral fins and a caudal fin is developed. The pectoral fin mechanism has 3 degrees of freedom （3-DOFs）, which enables the mbet fish to realize yawing and pitching motions by controlling two pectoral fins. And the eandal fin mechanism is designed based on fish body wave curve fitting. The forward velocity can be adjusted by changing the eandal mechanism＇ s oscillating frequency. Finally a physical implementation of the robot fish and experimental results are given.展开更多
A practical motion control strategy for a radio-controlled, 4-link and free-swimmingbiomimetic robot fish is presented. Based on control performance of the fish the fish s motion controltask is decomposed into on-line...A practical motion control strategy for a radio-controlled, 4-link and free-swimmingbiomimetic robot fish is presented. Based on control performance of the fish the fish s motion controltask is decomposed into on-line speed control and orientation control. The speed control algorithm isimplemented by using piecewise control, and orientation control is realized by fuzzy logic. Combiningwith step control and fuzzy control, a point-to-point (PTP) control algorithm is proposed and appliedto the closed-loop experimental system that uses a vision-based position sensing subsystem to providefeedback. Experiments confirm the reliability and e?ectiveness of the presented algorithms.展开更多
Compliant mobile robotics is a developing bioinspired concept of propulsion for locomotion.This paper studies the modeling and analysis of a compliant tail-propelled fish-like robot.This biomimetic design uses a fluid...Compliant mobile robotics is a developing bioinspired concept of propulsion for locomotion.This paper studies the modeling and analysis of a compliant tail-propelled fish-like robot.This biomimetic design uses a fluid-filled network of channels embedded into the soft body to actuate the compliant tail and generate thrust.This study analyzes the nonlinear dynamics of Fish Tail Fluidic Actuator(FTFA).The fluidic expansion under pressure creates a bending moment in the tail.It is demonstrated that the tail response follows the theoretical formulation extracted from the accurate modeling.In this modeling,tail is assumed as a continuous Euler–Bernoulli beam considering large deflection and nonlinear strain.Then,the implementation of Hamilton's principle and the method of calculation lead to the motion equations.The assumed mode method is used to achieve the mathematical model in the multi-mode system that is more similar to the soft continuous system.We investigate the tendencies of the tail amplitude,swimming speed,and Strouhal number when the input driving frequency changes.The simulation results disclose that high swimming efficiency can be obtained at the multi-order resonances;meanwhile,the compliant fish robot is pushed at the corresponding frequency illustrating nonlinear behavior.展开更多
Dielectric elastomer actuators(DEAs)are promising enabling devices which can be used in a wide range of robots,artificial muscles,and microfluidics.They are characterized by high actuating strain,low cost and noise,an...Dielectric elastomer actuators(DEAs)are promising enabling devices which can be used in a wide range of robots,artificial muscles,and microfluidics.They are characterized by high actuating strain,low cost and noise,and high energy density and efficiency.There are three main challenges for enabling DEs to become actuators:(i)developing suitable and compatible electrode materials;(ii)effectively isolating the actuator electrode from the surrounding fluid;and(iii)creating a rigid frame that usually requires prestraining of the dielectric layer.The use of robotic fish in water is an important application field of biomimetic soft robots.At present,most underwater robotic fish use spiral propulsion,which has several problems,including propulsion efficiency,position controllability and aquatic organism involvement.To provide solutions,the research and development of underwater robotic fish that imitate the fins and body propulsion of fish and the use of soft underwater robotic fish are in full adoption.This project involves the research and development of a bionic soft underwater robot fish with a software driver,which can imitate swimming via the tail fin and body of a fish,especially with respect to stable swimming propulsion,to successfully develop high-performance soft underwater robot fish.In addition,to imitate the unstable swimming movements of fish,such as turning and sharp acceleration and deceleration,robot fish that use DE drivers with good flexibility and high strain have been researched and developed.展开更多
In complex water environments,search tasks often involve multiple Autonomous Underwater Vehicles(AUVs),and a single centralized control cannot handle the complexity and computational burden of large-scale systems.Targ...In complex water environments,search tasks often involve multiple Autonomous Underwater Vehicles(AUVs),and a single centralized control cannot handle the complexity and computational burden of large-scale systems.Target search in complex water environments has always been a major challenge in the field of underwater robots.To address this problem,this paper proposes a multi-biomimetic robot fish collaborative target search method based on Distributed Model Predictive Control(DMPC).First,we established a bionic robot fish kinematic model and a multi-biomimetic robot fish communication model;second,this paper proposed a distributed model predictive control algorithm based on the distributed search theory framework,so that the bionic robot fish can dynamically adjust their search path according to each other’s position information and search status,avoid repeated coverage or missing areas,and thus improve the search efficiency;third,we conducted simulation experiments based on DMPC,and the results showed that the proposed method has a target search success rate of more than 90%in static targets,dynamic targets,and obstacle environments.Finally,we compared this method with Centralized Model Predictive Control(CMPC)and Random Walk(RW)algorithms.The DMPC approach demonstrates significant advantages,achieving a remarkable target search success rate of 94.17%.These findings comprehensively validate the effectiveness and superiority of the proposed methodology.It can be seen that DMPC can effectively dispatch multiple bionic robot fish to work together to achieve efficient search of vast waters.It can significantly improve the flexibility,scalability,robustness and cooperation efficiency of the system and has broad application prospects.展开更多
This work presents an adaptive tracking guidance method for robotic fishes. The scheme enables robots to suppress external interference and eliminate motion jitter. An adaptive integral surge line-of-sight guidance ru...This work presents an adaptive tracking guidance method for robotic fishes. The scheme enables robots to suppress external interference and eliminate motion jitter. An adaptive integral surge line-of-sight guidance rule is designed to eliminate dynamics interference and sideslip issues. Limited-time yaw and surge speed observers are reported to fit disturbance variables in the model. The approximation values can compensate for the system's control input and improve the robots' tracking accuracy.Moreover, this work develops a terminal sliding mode controller and third-order differential processor to determine the rotational torque and reduce the robots' run jitter. Then, Lyapunov's theory proves the uniform ultimate boundedness of the proposed method. Simulation and physical experiments confirm that the technology improves the tracking error convergence speed and stability of robotic fishes.展开更多
Thunniform swimmers(tuna)have a swinging narrow sequence stalk and a moon-shaped tail fin,which performs poorly at slow speed,higher acceleration and turning maneuverability.In most cases,faster speed and higher maneu...Thunniform swimmers(tuna)have a swinging narrow sequence stalk and a moon-shaped tail fin,which performs poorly at slow speed,higher acceleration and turning maneuverability.In most cases,faster speed and higher maneuverability are mutually rejection for most marine creatures and their robotic opponents.This paper presents a novel hybrid tuna-like swimming robot for aquaculture water quality monitoring,which interleaves faster speed and higher maneuverability.The robotic prototype emphasizes on streamlining and enhanced maneuverability mechanism designs in conjunction with a narrow caudal propeller to the tail.The innovative design endows the robot to easily execute the multi-mode swimming gait,including forward swimming,turning,diving/surfacing.The capabilities of our robot are validated through a series of indoor swimming pool and field breeding ponds.The robotic fish can achieve a maximum speed up to about 1.16 m/s and a minimum turning radius less than 0.46 Body Lengths(BL)and its maximum turning speed can reach 78.6∘/s.Due to its high speed,maneuverability and relatively small size,the robotic fish shed light on intelligent monitoring in complex aquatic environments.展开更多
A robotic fish driven by oscillating fins, 'Cownose Ray-I', is developed, which is in dorsoventrally flattened shape without a tail. The robotic fish is composed of a body and two lateral fins. A three-factor ...A robotic fish driven by oscillating fins, 'Cownose Ray-I', is developed, which is in dorsoventrally flattened shape without a tail. The robotic fish is composed of a body and two lateral fins. A three-factor kinematic model is established and used in the design of a mechanism. By controlling the three kinematic parameters, the robotic fish can accelerate and maneuver. Forward velocity is dependent on the largest amplitude and the number of waves in the fins, while the relative contribution of fin beat frequency to the forward velocity of the robotic fish is different from the usual result. On the other hand, experimental results on maneuvering show that phase difference has a stronger effect on swerving than the largest amplitude to some extent. In addition, as propulsion waves pass from the trailing edge to the leading edge, the robotic fish attains a backward velocity of 0. 15 m·s^(-1).展开更多
The cow-nosed ray is studied as natural sample of a flapping-foil robotic fish.Body structure, motion discipline, and dynamicfoil deformation of cow-nosed ray are analyzed.Based on the analysis results, a robotic fish...The cow-nosed ray is studied as natural sample of a flapping-foil robotic fish.Body structure, motion discipline, and dynamicfoil deformation of cow-nosed ray are analyzed.Based on the analysis results, a robotic fish imitating cow-nosed ray,named Robo-ray Ⅱ, mainly composed of soft body, flexible ribs and pneumatic artificial muscles, is developed.Structure andswimming morphology of the robotic prototype are as that of a normal cow-nosed ray in nature.Key propulsion parameters ofRobo-ray Ⅱ at normal conditions, including the St Number at linear swimming, thrust coefficient at towing are studied throughexperiments.The suitable driving parameters are confirmed considering the efficiency and swimming velocity.Swimmingvelocity of 0.16 m·s’and thrust coefficient of 0.56 in maximum are achieved in experiments.展开更多
In this paper, a carangiform robotic fish with 4-DoF （degree of freedom） tail has been developed. The robotic fish has capability of swimming under two modes that are radio control and autonomous swimming. Experimen...In this paper, a carangiform robotic fish with 4-DoF （degree of freedom） tail has been developed. The robotic fish has capability of swimming under two modes that are radio control and autonomous swimming. Experiments were conducted to investigate the influences of characteristic parameters including the frequency, the amplitude, the wave length, the phase difference and the coefficient on forward velocity. The experimental results shown that the swimming performance of the robotic fish is affected mostly by the characteristic parameters observed.展开更多
This paper addresses the design of a biomimetic fish robot actuated by piezoeeramic actuators and the effect of artificial caudal fins on the fish robot＇s performance. The limited bending displacement produced by a l...This paper addresses the design of a biomimetic fish robot actuated by piezoeeramic actuators and the effect of artificial caudal fins on the fish robot＇s performance. The limited bending displacement produced by a lightweight piezocomposite actuator was amplified and transformed into a large tail beat motion by means of a linkage system. Caudal fins that mimic the shape of a mackerel fin were fabricated for the purpose of examining the effect of caudal fm characteristics on thrust production at an operating frequency range. The thickness distribution of a real mackerel＇s fin was measured and used to design artificial caudal fins. The thrust performance of the biomimetic fish robot propelled by fins of various thicknesses was examined in terms of the Strouhal number, the Froude number, the Reynolds number, and the power consumption. For the same fm area and aspect ratio, an artificial caudal fin with a distributed thickness shows the best forward speed and the least power consumption.展开更多
文摘The disadvantages caused by the swing of a fish body were analyzed. The coordinate system of a two-joint robot fish was built. The hydrodynamic analysis of robot fish was developed. The dynamic simulation of a two-joint robot fish was carried out with the ADAMS software. The relationship between the swing of fish body and the mass distribution of robot fish, the relationship between the swing of fish body and the swing frequency of tail, were gained. The impact of the swing of fish body on the kinematic parameters of tail fin was analyzed. Three methods to restrain the swing of fish body were presented and discussed.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(class A)(Grant No.XDA22040203)the Fundamental Research Funds for the Central Universities(Grant No.2019XX01)+1 种基金GDNRC[2020]031the Natural Science Foundation of Guangdong Province(Grant No.2020A1515010621).
文摘This paper presents a study on bioinspired closed-loop Central Pattern Generator(CPG)based control of a robot fish for obstacle avoidance and direction tracking.The biomimetic robot fish is made of a rigid head with a pair of pectoral fins,a wire-driven active body covered with soft skin,and a compliant tail.The CPG model consists of four input parameters:the flapping amplitude,the flapping angular velocity,the flapping offset,and the time ratio between the beat phase and the restore phase in flapping.The robot fish is equipped with three infrared sensors mounted on the left,front and right of the robot fish,as well as an inertial measurement unit,from which the surrounding obstacles and moving direction can be sensed.Based on these sensor signals,the closed-loop CPG-based control can drive the robot fish to avoid obstacles and to track designated directions.Four sets of experiments are presented,including avoiding a static obstacle,avoiding a moving obstacle,tracking a designated direction and tracking a designated direction with an obstacle in the path.The experiment results indicated that the presented control strategy worked well and the robot fish can accomplish the obstacle avoidance and direction tracking effectively.
文摘As a combination of bio-mechanism and engineering technology, robot fish has become a multidisci- plinary research that mainly involves both hydrodynamics-based control and actuation technology. This paper presents a simplified propulsive model for carangiform propulsion, which is a swimming mode suitable for high speed and high efficiency. The carangiform motion is modeled as an N-joint nscillating mechanism that is composed of two basic components： the streamlined fish body represented by a planar spline curve and its hmate caudal tail by an oscillating foil. The speed of fish＇s straight swimming is adjusted by modulating the joint＇s oscillating frequency, and its orientation is tuned by different joint＇s deflection. The results from actual experiment showed that the proposed simplified propulsive model could be a viable eandidate for application in aquatic： swimming vehicles.
基金This work was supported by National 973 Program (No. 2002CB312200) and National Hi-tech Development Project (No. 2003AA404190)
文摘This paper concerns with 3-D locomotion control methods for a biomimetic robot fish. The system architecture of the fish is firstly presented based on a physical model of carangiform fish. The robot fish has a flexible body, a rigid caudal fin and a pair of pectoral fins, driven by several servomotors. The motion control of the robot fish are then divided into speed control, orientation control, submerge control and transient motion control, corresponding algorithms are detailed respectively. Finally, experiments and analyses on a 4-link, radio-controlled robot fish prototype with 3-D locomotion show its good performance.
基金Supported by the National Natural Science Foundation of China （No. 50475179） and the National High Technology, Research and Development Program of China （No. 2006AAllz225）.
文摘A mechanical design method of mbet fish is introduced in this paper. Based on this method, an autonomous 3-Dimension （3D） locomotion mbet fish with two pectoral fins and a caudal fin is developed. The pectoral fin mechanism has 3 degrees of freedom （3-DOFs）, which enables the mbet fish to realize yawing and pitching motions by controlling two pectoral fins. And the eandal fin mechanism is designed based on fish body wave curve fitting. The forward velocity can be adjusted by changing the eandal mechanism＇ s oscillating frequency. Finally a physical implementation of the robot fish and experimental results are given.
文摘A practical motion control strategy for a radio-controlled, 4-link and free-swimmingbiomimetic robot fish is presented. Based on control performance of the fish the fish s motion controltask is decomposed into on-line speed control and orientation control. The speed control algorithm isimplemented by using piecewise control, and orientation control is realized by fuzzy logic. Combiningwith step control and fuzzy control, a point-to-point (PTP) control algorithm is proposed and appliedto the closed-loop experimental system that uses a vision-based position sensing subsystem to providefeedback. Experiments confirm the reliability and e?ectiveness of the presented algorithms.
文摘Compliant mobile robotics is a developing bioinspired concept of propulsion for locomotion.This paper studies the modeling and analysis of a compliant tail-propelled fish-like robot.This biomimetic design uses a fluid-filled network of channels embedded into the soft body to actuate the compliant tail and generate thrust.This study analyzes the nonlinear dynamics of Fish Tail Fluidic Actuator(FTFA).The fluidic expansion under pressure creates a bending moment in the tail.It is demonstrated that the tail response follows the theoretical formulation extracted from the accurate modeling.In this modeling,tail is assumed as a continuous Euler–Bernoulli beam considering large deflection and nonlinear strain.Then,the implementation of Hamilton's principle and the method of calculation lead to the motion equations.The assumed mode method is used to achieve the mathematical model in the multi-mode system that is more similar to the soft continuous system.We investigate the tendencies of the tail amplitude,swimming speed,and Strouhal number when the input driving frequency changes.The simulation results disclose that high swimming efficiency can be obtained at the multi-order resonances;meanwhile,the compliant fish robot is pushed at the corresponding frequency illustrating nonlinear behavior.
基金Project supported by Joint Open Fund of Guizhou Provincial Department of Education(Grant No.[2022]439)the Academic New Seedling Cultivation and Free Exploration and Innovation of Guizhou Provincial Science and Technology Department(Grant No.[2023]11).
文摘Dielectric elastomer actuators(DEAs)are promising enabling devices which can be used in a wide range of robots,artificial muscles,and microfluidics.They are characterized by high actuating strain,low cost and noise,and high energy density and efficiency.There are three main challenges for enabling DEs to become actuators:(i)developing suitable and compatible electrode materials;(ii)effectively isolating the actuator electrode from the surrounding fluid;and(iii)creating a rigid frame that usually requires prestraining of the dielectric layer.The use of robotic fish in water is an important application field of biomimetic soft robots.At present,most underwater robotic fish use spiral propulsion,which has several problems,including propulsion efficiency,position controllability and aquatic organism involvement.To provide solutions,the research and development of underwater robotic fish that imitate the fins and body propulsion of fish and the use of soft underwater robotic fish are in full adoption.This project involves the research and development of a bionic soft underwater robot fish with a software driver,which can imitate swimming via the tail fin and body of a fish,especially with respect to stable swimming propulsion,to successfully develop high-performance soft underwater robot fish.In addition,to imitate the unstable swimming movements of fish,such as turning and sharp acceleration and deceleration,robot fish that use DE drivers with good flexibility and high strain have been researched and developed.
基金funded by National Natural Science Foundation of China(Nos.62473236,62073196).
文摘In complex water environments,search tasks often involve multiple Autonomous Underwater Vehicles(AUVs),and a single centralized control cannot handle the complexity and computational burden of large-scale systems.Target search in complex water environments has always been a major challenge in the field of underwater robots.To address this problem,this paper proposes a multi-biomimetic robot fish collaborative target search method based on Distributed Model Predictive Control(DMPC).First,we established a bionic robot fish kinematic model and a multi-biomimetic robot fish communication model;second,this paper proposed a distributed model predictive control algorithm based on the distributed search theory framework,so that the bionic robot fish can dynamically adjust their search path according to each other’s position information and search status,avoid repeated coverage or missing areas,and thus improve the search efficiency;third,we conducted simulation experiments based on DMPC,and the results showed that the proposed method has a target search success rate of more than 90%in static targets,dynamic targets,and obstacle environments.Finally,we compared this method with Centralized Model Predictive Control(CMPC)and Random Walk(RW)algorithms.The DMPC approach demonstrates significant advantages,achieving a remarkable target search success rate of 94.17%.These findings comprehensively validate the effectiveness and superiority of the proposed methodology.It can be seen that DMPC can effectively dispatch multiple bionic robot fish to work together to achieve efficient search of vast waters.It can significantly improve the flexibility,scalability,robustness and cooperation efficiency of the system and has broad application prospects.
基金supported in part by the National Natural Science Foundation of China(62303117,T2325018,92367109)the Xiangjiang Scholar Program(XJ2023018)+2 种基金the Key Laboratory of System Control and Information Processing(Scip20240108)the Aeronautical Science Foundation of China(20230001144001)Fujian Provincial Natural Science Foundation(2024J01130098)
文摘This work presents an adaptive tracking guidance method for robotic fishes. The scheme enables robots to suppress external interference and eliminate motion jitter. An adaptive integral surge line-of-sight guidance rule is designed to eliminate dynamics interference and sideslip issues. Limited-time yaw and surge speed observers are reported to fit disturbance variables in the model. The approximation values can compensate for the system's control input and improve the robots' tracking accuracy.Moreover, this work develops a terminal sliding mode controller and third-order differential processor to determine the rotational torque and reduce the robots' run jitter. Then, Lyapunov's theory proves the uniform ultimate boundedness of the proposed method. Simulation and physical experiments confirm that the technology improves the tracking error convergence speed and stability of robotic fishes.
基金the National Key R&D Program of China(2022YFE0107100)the National Key R&D Programs of China(Grant No.2019YFD0901000)the National Natural Science Foundation of China(Grant No.61903007).
文摘Thunniform swimmers(tuna)have a swinging narrow sequence stalk and a moon-shaped tail fin,which performs poorly at slow speed,higher acceleration and turning maneuverability.In most cases,faster speed and higher maneuverability are mutually rejection for most marine creatures and their robotic opponents.This paper presents a novel hybrid tuna-like swimming robot for aquaculture water quality monitoring,which interleaves faster speed and higher maneuverability.The robotic prototype emphasizes on streamlining and enhanced maneuverability mechanism designs in conjunction with a narrow caudal propeller to the tail.The innovative design endows the robot to easily execute the multi-mode swimming gait,including forward swimming,turning,diving/surfacing.The capabilities of our robot are validated through a series of indoor swimming pool and field breeding ponds.The robotic fish can achieve a maximum speed up to about 1.16 m/s and a minimum turning radius less than 0.46 Body Lengths(BL)and its maximum turning speed can reach 78.6∘/s.Due to its high speed,maneuverability and relatively small size,the robotic fish shed light on intelligent monitoring in complex aquatic environments.
基金The supports of National Natural Science Foundation of China (No.50405006)the supports of the innovation foundation of graduate students of National University of Defense Technology (No.B060302) are also gratefully acknowledged
文摘A robotic fish driven by oscillating fins, 'Cownose Ray-I', is developed, which is in dorsoventrally flattened shape without a tail. The robotic fish is composed of a body and two lateral fins. A three-factor kinematic model is established and used in the design of a mechanism. By controlling the three kinematic parameters, the robotic fish can accelerate and maneuver. Forward velocity is dependent on the largest amplitude and the number of waves in the fins, while the relative contribution of fin beat frequency to the forward velocity of the robotic fish is different from the usual result. On the other hand, experimental results on maneuvering show that phase difference has a stronger effect on swerving than the largest amplitude to some extent. In addition, as propulsion waves pass from the trailing edge to the leading edge, the robotic fish attains a backward velocity of 0. 15 m·s^(-1).
基金supported by the National High Technology Research and Development Program of China(863 Program)Program for New Century Excellent Talents in University
文摘The cow-nosed ray is studied as natural sample of a flapping-foil robotic fish.Body structure, motion discipline, and dynamicfoil deformation of cow-nosed ray are analyzed.Based on the analysis results, a robotic fish imitating cow-nosed ray,named Robo-ray Ⅱ, mainly composed of soft body, flexible ribs and pneumatic artificial muscles, is developed.Structure andswimming morphology of the robotic prototype are as that of a normal cow-nosed ray in nature.Key propulsion parameters ofRobo-ray Ⅱ at normal conditions, including the St Number at linear swimming, thrust coefficient at towing are studied throughexperiments.The suitable driving parameters are confirmed considering the efficiency and swimming velocity.Swimmingvelocity of 0.16 m·s’and thrust coefficient of 0.56 in maximum are achieved in experiments.
文摘In this paper, a carangiform robotic fish with 4-DoF （degree of freedom） tail has been developed. The robotic fish has capability of swimming under two modes that are radio control and autonomous swimming. Experiments were conducted to investigate the influences of characteristic parameters including the frequency, the amplitude, the wave length, the phase difference and the coefficient on forward velocity. The experimental results shown that the swimming performance of the robotic fish is affected mostly by the characteristic parameters observed.
文摘This paper addresses the design of a biomimetic fish robot actuated by piezoeeramic actuators and the effect of artificial caudal fins on the fish robot＇s performance. The limited bending displacement produced by a lightweight piezocomposite actuator was amplified and transformed into a large tail beat motion by means of a linkage system. Caudal fins that mimic the shape of a mackerel fin were fabricated for the purpose of examining the effect of caudal fm characteristics on thrust production at an operating frequency range. The thickness distribution of a real mackerel＇s fin was measured and used to design artificial caudal fins. The thrust performance of the biomimetic fish robot propelled by fins of various thicknesses was examined in terms of the Strouhal number, the Froude number, the Reynolds number, and the power consumption. For the same fm area and aspect ratio, an artificial caudal fin with a distributed thickness shows the best forward speed and the least power consumption.
