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
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
Soft robots,as a modern gateway to unlocking the mysteries of underwater realms,present new complexities.Modeling their behavior when in contact with external forces,whether point-based or distributed,is a primary cha...Soft robots,as a modern gateway to unlocking the mysteries of underwater realms,present new complexities.Modeling their behavior when in contact with external forces,whether point-based or distributed,is a primary challenge due to the nature of soft bodies.To obtain a holistic view of the system’s behavior determining the governing dynamics is deemed necessary.This paper proposes a new technique to simulate the dynamic lateral undulation of a soft robotic fish with a cable-driven soft tail.By integrating the rigid finite element method with rigid-body robotics,the model represents the undulation of a finite number of rigid elements connected through a set of torsional spring and damper.Instead of directly modeling external forces,we substitute equivalent joint torques into the system dynamics,allowing us to consider external effects without complicating the model.The resulting model yields valuable insights into the system’s behavior,including propulsive and lateral forces.A comparison with experimental results shows strong agreement,with a tip amplitude error of 10% at 0.8 Hz,5.25% at 1.6 Hz and 2.54%at 2.2 Hz flapping frequency.These findings illuminate the influence of lateral undulation on the overall dynamics,paving the way for fully autonomous robotic fish.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
In present,there are increasing interests in the research on mechanical and control system of underwater vehicles.These ongoing research efforts are motivated by more pervasive applications of such vehicles including ...In present,there are increasing interests in the research on mechanical and control system of underwater vehicles.These ongoing research efforts are motivated by more pervasive applications of such vehicles including seabed oil and gas explorations, scientific deep ocean surveys,military purposes,ecological and water environmental studies,and also entertainments. However,the performance of underwater vehicles with screw type propellers is not prospective in terms of its efficiency and maneuverability.The main weaknesses of this kind of propellers are the production of vortices and sudden generation of thrust forces which make the control of the position and motion difficult. On the other hand,fishes and other aquatic animals are efficient swimmers,posses high maneuverability,are able to follow trajectories,can efficiently stabilize themselves in currents and surges,create less wakes than currently used underwater vehicle, and also have a noiseless propulsion.The fish's locomotion mechanism is mainly controlled by its caudal fin and paired pectoral fins.They are classified into Body and/or Caudal Fin(BCF)and Median and/or paired Pectoral Fins(MPF).The study of highly efficient swimming mechanisms of fish can inspire a better underwater vehicles thruster design and its mechanism. There are few studies on underwater vehicles or fish robots using paired pectoral fins as thruster.The work presented in this paper represents a contribution in this area covering study,design and implementation of locomotion mechanisms of paired pectoral fins in a fish robot.The performance and viability of the biomimetic method for underwater vehicles are highlighted through in-water experiment of a robotic fish.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
Over the past 20 years, experimental analyses of the biomechanics of locomotion in fishes have generated a number of key findings that are relevant to the construction of biomimetic fish robots. In this paper, we pres...Over the past 20 years, experimental analyses of the biomechanics of locomotion in fishes have generated a number of key findings that are relevant to the construction of biomimetic fish robots. In this paper, we present 16 results from recent experimental research on the mechanics, kinematics, fluid dynamics, and control of fish locomotion that summarize recent work on fish biomechanics. The findings and principles that have emerged from biomechanical studies of fish locomotion provide important insights into the functional design of fishes and suggest specific design features relevant to construction of robotic fish-inspired vehicles that underlie the high locomotor performance exhibited by fishes.展开更多
Underwater robot is a new research field which is emerging quickly in recent years.Previous researches in this field focus on Remotely Operated Vehicles(ROVs),Autonomous Underwater Vehicles(AUVs),underwater manipulato...Underwater robot is a new research field which is emerging quickly in recent years.Previous researches in this field focus on Remotely Operated Vehicles(ROVs),Autonomous Underwater Vehicles(AUVs),underwater manipulators,etc.Fish robot, which is a new type of underwater biomimetic robot,has attracted great attention because of its silence in moving and energy efficiency compared to conventional propeller-oriented propulsive mechanism. However,most of researches on fish robots have been carried out via empirical or experimental approaches,not based on dynamic optimality.In this paper,we proposed an analytical optimization approach which can guarantee the maximum propulsive velocity of fish robot in the given parametric conditions.First,a dynamic model of 3-joint(4 links)carangiform fish robot is derived,using which the influences of parameters of input torque functions,such as amplitude,frequency and phase difference,on its velocity are investigated by simulation.Second,the maximum velocity of the fish robot is optimized by combining Genetic Algorithm(GA)and Hill Climbing Algorithm(HCA).GA is used to generate the initial optimal parameters of the input functions of the system.Then,the parameters are optimized again by HCA to ensure that the final set of parameters is the'near'global optimization.Finally,both simulations and primitive experiments are carried out to prove the feasibility of the proposed method.展开更多
This paper presents a 3D simulator used for studying the motion control and autonomous navigation of robotic fish. The simulator’s system structure and computation flow are presented. Simplified kinematics and hydrod...This paper presents a 3D simulator used for studying the motion control and autonomous navigation of robotic fish. The simulator’s system structure and computation flow are presented. Simplified kinematics and hydrodynamics models for a virtual robotic fish are proposed. Many other object models are created for water, obstacles, sonar sensors and a swimming pool. Experimental results show that the simulator provides a realistic and convenient way to develop autonomous navigation algorithms for robotic fish.展开更多
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.
文摘Soft robots,as a modern gateway to unlocking the mysteries of underwater realms,present new complexities.Modeling their behavior when in contact with external forces,whether point-based or distributed,is a primary challenge due to the nature of soft bodies.To obtain a holistic view of the system’s behavior determining the governing dynamics is deemed necessary.This paper proposes a new technique to simulate the dynamic lateral undulation of a soft robotic fish with a cable-driven soft tail.By integrating the rigid finite element method with rigid-body robotics,the model represents the undulation of a finite number of rigid elements connected through a set of torsional spring and damper.Instead of directly modeling external forces,we substitute equivalent joint torques into the system dynamics,allowing us to consider external effects without complicating the model.The resulting model yields valuable insights into the system’s behavior,including propulsive and lateral forces.A comparison with experimental results shows strong agreement,with a tip amplitude error of 10% at 0.8 Hz,5.25% at 1.6 Hz and 2.54%at 2.2 Hz flapping frequency.These findings illuminate the influence of lateral undulation on the overall dynamics,paving the way for fully autonomous robotic fish.
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.
文摘In present,there are increasing interests in the research on mechanical and control system of underwater vehicles.These ongoing research efforts are motivated by more pervasive applications of such vehicles including seabed oil and gas explorations, scientific deep ocean surveys,military purposes,ecological and water environmental studies,and also entertainments. However,the performance of underwater vehicles with screw type propellers is not prospective in terms of its efficiency and maneuverability.The main weaknesses of this kind of propellers are the production of vortices and sudden generation of thrust forces which make the control of the position and motion difficult. On the other hand,fishes and other aquatic animals are efficient swimmers,posses high maneuverability,are able to follow trajectories,can efficiently stabilize themselves in currents and surges,create less wakes than currently used underwater vehicle, and also have a noiseless propulsion.The fish's locomotion mechanism is mainly controlled by its caudal fin and paired pectoral fins.They are classified into Body and/or Caudal Fin(BCF)and Median and/or paired Pectoral Fins(MPF).The study of highly efficient swimming mechanisms of fish can inspire a better underwater vehicles thruster design and its mechanism. There are few studies on underwater vehicles or fish robots using paired pectoral fins as thruster.The work presented in this paper represents a contribution in this area covering study,design and implementation of locomotion mechanisms of paired pectoral fins in a fish robot.The performance and viability of the biomimetic method for underwater vehicles are highlighted through in-water experiment of a robotic fish.
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.
基金This work was supported in part by an Office of Naval Research (USA) MURI grantgrants from the National Science Foundation to George Lauder
文摘Over the past 20 years, experimental analyses of the biomechanics of locomotion in fishes have generated a number of key findings that are relevant to the construction of biomimetic fish robots. In this paper, we present 16 results from recent experimental research on the mechanics, kinematics, fluid dynamics, and control of fish locomotion that summarize recent work on fish biomechanics. The findings and principles that have emerged from biomechanical studies of fish locomotion provide important insights into the functional design of fishes and suggest specific design features relevant to construction of robotic fish-inspired vehicles that underlie the high locomotor performance exhibited by fishes.
文摘Underwater robot is a new research field which is emerging quickly in recent years.Previous researches in this field focus on Remotely Operated Vehicles(ROVs),Autonomous Underwater Vehicles(AUVs),underwater manipulators,etc.Fish robot, which is a new type of underwater biomimetic robot,has attracted great attention because of its silence in moving and energy efficiency compared to conventional propeller-oriented propulsive mechanism. However,most of researches on fish robots have been carried out via empirical or experimental approaches,not based on dynamic optimality.In this paper,we proposed an analytical optimization approach which can guarantee the maximum propulsive velocity of fish robot in the given parametric conditions.First,a dynamic model of 3-joint(4 links)carangiform fish robot is derived,using which the influences of parameters of input torque functions,such as amplitude,frequency and phase difference,on its velocity are investigated by simulation.Second,the maximum velocity of the fish robot is optimized by combining Genetic Algorithm(GA)and Hill Climbing Algorithm(HCA).GA is used to generate the initial optimal parameters of the input functions of the system.Then,the parameters are optimized again by HCA to ensure that the final set of parameters is the'near'global optimization.Finally,both simulations and primitive experiments are carried out to prove the feasibility of the proposed method.
文摘This paper presents a 3D simulator used for studying the motion control and autonomous navigation of robotic fish. The simulator’s system structure and computation flow are presented. Simplified kinematics and hydrodynamics models for a virtual robotic fish are proposed. Many other object models are created for water, obstacles, sonar sensors and a swimming pool. Experimental results show that the simulator provides a realistic and convenient way to develop autonomous navigation algorithms for robotic fish.
