A simplified model of the thrust force is proposed based on a caudal fin oscillation of an underwater bionic robot. The caudal fin oscillation is generalized by cen- tral pattern generators （CPGs）. In this model, th...A simplified model of the thrust force is proposed based on a caudal fin oscillation of an underwater bionic robot. The caudal fin oscillation is generalized by cen- tral pattern generators （CPGs）. In this model, the drag coefficient and lift coefficient are the two critical parameters which are obtained by the digital particle image velocimetry （DPIV） and the force transducer experiment. Numerical simulation and physical experi- ments have been performed to verify this dynamic model.展开更多
Spinning gait is valuable for quadruped robot,which can be used to avoid obstacles quickly for robot walking in unstructured environment. A kind of bionic flexible body is presented for quadruped robot to perform the ...Spinning gait is valuable for quadruped robot,which can be used to avoid obstacles quickly for robot walking in unstructured environment. A kind of bionic flexible body is presented for quadruped robot to perform the spinning gait. The spinning gait can be achieved by coordinated movement of body laterally bending and legs swing,which can improve the mobility of robot walking in the unstructured environments. The coordinated movement relationship between the body and the leg mechanism is presented. The stability of quadruped robot with spinning gait is analyzed based on the center of gravity( COG) projection method. The effect of different body bending angle on the stability of quadruped robot with spinning gait is mainly studied. For the quadruped robot walking with spinning gait,during one spinning gait cycle,the supporting polygon and the trajectory of COG projection point under different body bending angle are calculated. Finally,the stability margin of quadruped robot with spinning gait under different body bending angle is determined,which can be used to evaluate reasonableness of spinning gait parameters.展开更多
Variable Stiffness Actuation(VSA)is an efficient,safe,and robust actuation technology for bionic robotic joints that have emerged in recent decades.By introducing a variable stiffness elastomer in the actuation system...Variable Stiffness Actuation(VSA)is an efficient,safe,and robust actuation technology for bionic robotic joints that have emerged in recent decades.By introducing a variable stiffness elastomer in the actuation system,the mechanical-electric energy conversion between the motor and the load could be adjusted on-demand,thereby improving the performance of the actuator,such as the peak power reduction,energy saving,bionic actuation,etc.At present,the VSA technology has achieved fruitful research results in designing the actuator mechanism and the stiffness adjustment servo,which has been widely applied in articulated robots,exoskeletons,prostheses,etc.However,how to optimally control the stiffness of VSAs in different application scenarios for better actuator performance is still challenging,where there is still a lack of unified cognition and viewpoints.Therefore,from the perspective of optimal VSA performance,this paper first introduces some typical structural design and servo control techniques of common VSAs and then explains the methods and applications of the Optimal Variable Stiffness Control(OVSC)approaches by theoretically introducing different types of OVSC mathematical models and summarizing OVSC methods with varying optimization goals and application scenarios or cases.In addition,the current research challenges of OVSC methods and possible innovative insights are also presented and discussed in-depth to facilitate the future development of VSA control.展开更多
With the increasing impacts of overfishing and environmental pollution,the deep-sea cage culture of marine fishes has become an important direction of mariculture.In this paper,a tuna-like robotic fish with a three-di...With the increasing impacts of overfishing and environmental pollution,the deep-sea cage culture of marine fishes has become an important direction of mariculture.In this paper,a tuna-like robotic fish with a three-dimensional helix path-following control system is designed for deep-sea net cage inspection.To mimic the flexibility of the fish’s movement,the kinematic model of the robotic fish adopts a tuna-like double-joint design with an addi-tional thruster device at the tail.Since the descending interval control plays a critical role in deep-sea net cage inspection,the control system utilizes the proportion integration differ-entiation(PID)based fuzzy logic control method to control the descending interval and yaw angle during the helix path movement.A polar coordinate path definition method is also proposed to simplify the reference path definition during net cage inspection.The experi-mental results demonstrates that the proposed three-dimensional path-following model can conduct net inspection task in an interferential environment and move along prede-fined reference path.展开更多
The body of quadruped robot is generally developed with the rigid structure. The mobility of quadruped robot depcnds on the mechanical properties of the body mechanism, It is difficult for quadruped robot with rigid s...The body of quadruped robot is generally developed with the rigid structure. The mobility of quadruped robot depcnds on the mechanical properties of the body mechanism, It is difficult for quadruped robot with rigid structure to achieve better mobility walking or running in the unstructured environment. A kind of bionic flexible body mechanism for quadruped robot is proposed, which is composed of one bionic spine and four pneumatic artificial muscles（PAMs）. This kind of body imitates the four-legged creatures＇ kinematical structure and physical properties, which has the characteristic of changeable stiff＇hess, lightweight, flexible and better bionics. The kinematics of body bending is derived, and the coordinated movement between the flexible body and legs is analyzed. The relationship between the body bending angle and the PAM length is obtained. The dynamics of the body bending is derived by the floating coordinate method and Lagrangian method, and the driving tbrce of PAM is determined. The experiment of body bending is conductcd, and the dynamic bending characteristic of bionic flexible body is evaluated. Experimental results show that the bending angle of the bionic flexible body can reach 18. An innovation body mechanism for quadruped robot is proposed, which has the characteristic of flexibility and achieve bending by changing gas pressure of PAMs. The coordinated movement of the body and legs can achieve spinning gait in order to improve the mobility of quadruped robot.展开更多
A flexible-rigid hopping mechanism which is inspired by the locust jumping was proposed, and its kinematic characteris- tics were analyzed. A series of experiments were conducted to observe locust morphology and jumpi...A flexible-rigid hopping mechanism which is inspired by the locust jumping was proposed, and its kinematic characteris- tics were analyzed. A series of experiments were conducted to observe locust morphology and jumping process. According to classic mechanics, the jumping process analysis was conducted to build the relationship of the locust jumping parameters. The take-offphase was divided into four stages in detail. Based on the biological observation and kinematics analysis, a mechanical model was proposed to simulate locust jumping. The forces of the flexible-rigid hopping mechanism at each stage were ana- lyzed. The kinematic analysis using pseudo-rigid-body model was described by D-H method. It is confirmed that the proposed bionic mechanism has the similar performance as the locust hind leg in hopping. Moreover, the jumping angle which decides the jumping process was discussed, and its relation with other parameters was established. A calculation case analysis corroborated the method. The results of this paper show that the proposed bionic mechanism which is inspired by the locust hind limb has an excellent kinematics performance, which can provide a foundation for design and motion planning of the hopping robot.展开更多
The paper presents the design of walking leg for bionics crab-like robot, which is driven with micro servo motor. The kinematic characteristics of the bionics machine are analysed for optimized structure parameters, w...The paper presents the design of walking leg for bionics crab-like robot, which is driven with micro servo motor. The kinematic characteristics of the bionics machine are analysed for optimized structure parameters, which has been used in the robot design. A three closed loop motor control system structure for joint driver is also given, as well as the multi-joint driving system for walking robot leg.展开更多
A quadruped robot is more adjustable to a complex terrain than a wheeled or caterpillar robot to realize the continuous adjustable motions characterized by submissiveness and low energy consumption in basic control of...A quadruped robot is more adjustable to a complex terrain than a wheeled or caterpillar robot to realize the continuous adjustable motions characterized by submissiveness and low energy consumption in basic control of the quadruped robot over rough terrain. This paper presents a static walking mode of ＂altitude hold＂, which means to keep absolute altitude by controlling limbs adjustably on the basis of which biokinetics studies have shown that quadrupeds can move with almost the same body altitude over rough terrains characterized by a nearly horizontal relief. The gait design specifies several characteristic states of stance phase and swing phase for a quadruped robot and controls the phase sequence and phase of four legs through change of characteristic states. Furthermore, we design a robot control system to generate adjustable gaits and control the coordinative movement of robot joints. This planning method is tested through ADAMS and MATLAB interactive co-simulation; the quadruped robot which has 8 degrees of freedom （8-DOF） is used to simulate the motion over a terrain character- ized by randomly arranged humps. The results show that this method can make the quadruped robot capable to walk over certain rough terrain.展开更多
为满足仿生机器鱼目标检测的需要,在YOLOv5基础上提出了一种轻量级检测算法,降低算法复杂度并提高精度。首先对YOLOv5s模型进行改进,通过GhostConv和C3Ghost模块降低参数量和计算量。其次,引入CA和CoordConv模块增强特征提取和目标位置...为满足仿生机器鱼目标检测的需要,在YOLOv5基础上提出了一种轻量级检测算法,降低算法复杂度并提高精度。首先对YOLOv5s模型进行改进,通过GhostConv和C3Ghost模块降低参数量和计算量。其次,引入CA和CoordConv模块增强特征提取和目标位置感知能力,采用soft NMS减少使用传统非极大抑制(Non maximum suppression,NMS)带来的漏检、误检,同时使用MPDIoU简化相似性比较,提升检测精度和召回率。最后,所提出方法在目标检测数据集上的试验结果表明,改进的YOLOv5网络体积更小、精度更高,证明了该算法的有效性和优越性。展开更多
基金Project supported by the National Natural Science Foundation of China(Nos.61503008 and 51575005)the China Postdoctoral Science Foundation(No.2015M570013)
文摘A simplified model of the thrust force is proposed based on a caudal fin oscillation of an underwater bionic robot. The caudal fin oscillation is generalized by cen- tral pattern generators （CPGs）. In this model, the drag coefficient and lift coefficient are the two critical parameters which are obtained by the digital particle image velocimetry （DPIV） and the force transducer experiment. Numerical simulation and physical experi- ments have been performed to verify this dynamic model.
基金Supported by the National Natural Science Foundation of China(No.51375289)Shanghai Municipal National Natural Science Foundation of China(No.13ZR1415500)Innovation Fund of Shanghai Education Commission(No.13YZ020)
文摘Spinning gait is valuable for quadruped robot,which can be used to avoid obstacles quickly for robot walking in unstructured environment. A kind of bionic flexible body is presented for quadruped robot to perform the spinning gait. The spinning gait can be achieved by coordinated movement of body laterally bending and legs swing,which can improve the mobility of robot walking in the unstructured environments. The coordinated movement relationship between the body and the leg mechanism is presented. The stability of quadruped robot with spinning gait is analyzed based on the center of gravity( COG) projection method. The effect of different body bending angle on the stability of quadruped robot with spinning gait is mainly studied. For the quadruped robot walking with spinning gait,during one spinning gait cycle,the supporting polygon and the trajectory of COG projection point under different body bending angle are calculated. Finally,the stability margin of quadruped robot with spinning gait under different body bending angle is determined,which can be used to evaluate reasonableness of spinning gait parameters.
基金National Key Research and Development Program of China[Grant No.2020YFB1313000]National Natural Science Foundation of China[Grant No.62003060,62101086,51975070]+2 种基金China Postdoctoral Science Foundation[2021M693769]Natural Science Foundation of Chongqing,China[Grant No.cstc2021jcyj-bsh0180]Scientific and Technological Research Program of Chongqing Municipal Education Commission[Grant No.KJQN202100648].
文摘Variable Stiffness Actuation(VSA)is an efficient,safe,and robust actuation technology for bionic robotic joints that have emerged in recent decades.By introducing a variable stiffness elastomer in the actuation system,the mechanical-electric energy conversion between the motor and the load could be adjusted on-demand,thereby improving the performance of the actuator,such as the peak power reduction,energy saving,bionic actuation,etc.At present,the VSA technology has achieved fruitful research results in designing the actuator mechanism and the stiffness adjustment servo,which has been widely applied in articulated robots,exoskeletons,prostheses,etc.However,how to optimally control the stiffness of VSAs in different application scenarios for better actuator performance is still challenging,where there is still a lack of unified cognition and viewpoints.Therefore,from the perspective of optimal VSA performance,this paper first introduces some typical structural design and servo control techniques of common VSAs and then explains the methods and applications of the Optimal Variable Stiffness Control(OVSC)approaches by theoretically introducing different types of OVSC mathematical models and summarizing OVSC methods with varying optimization goals and application scenarios or cases.In addition,the current research challenges of OVSC methods and possible innovative insights are also presented and discussed in-depth to facilitate the future development of VSA control.
基金This work is supported by the National Key Research and Development Program of China(Grant No.2019YFD0901000)the Key Technical Cooperation of Coastal Deep-water Probe(Grant No.2015DFA00090).
文摘With the increasing impacts of overfishing and environmental pollution,the deep-sea cage culture of marine fishes has become an important direction of mariculture.In this paper,a tuna-like robotic fish with a three-dimensional helix path-following control system is designed for deep-sea net cage inspection.To mimic the flexibility of the fish’s movement,the kinematic model of the robotic fish adopts a tuna-like double-joint design with an addi-tional thruster device at the tail.Since the descending interval control plays a critical role in deep-sea net cage inspection,the control system utilizes the proportion integration differ-entiation(PID)based fuzzy logic control method to control the descending interval and yaw angle during the helix path movement.A polar coordinate path definition method is also proposed to simplify the reference path definition during net cage inspection.The experi-mental results demonstrates that the proposed three-dimensional path-following model can conduct net inspection task in an interferential environment and move along prede-fined reference path.
基金Supported by National Natural Science Foundation of China(Grant No.51375289)Shanghai Municipal Natural Science Foundation of China(Grant No.13ZR1415500)Innovation Fund of Shanghai Education Commission(Grant No.13YZ020)
文摘The body of quadruped robot is generally developed with the rigid structure. The mobility of quadruped robot depcnds on the mechanical properties of the body mechanism, It is difficult for quadruped robot with rigid structure to achieve better mobility walking or running in the unstructured environment. A kind of bionic flexible body mechanism for quadruped robot is proposed, which is composed of one bionic spine and four pneumatic artificial muscles（PAMs）. This kind of body imitates the four-legged creatures＇ kinematical structure and physical properties, which has the characteristic of changeable stiff＇hess, lightweight, flexible and better bionics. The kinematics of body bending is derived, and the coordinated movement between the flexible body and legs is analyzed. The relationship between the body bending angle and the PAM length is obtained. The dynamics of the body bending is derived by the floating coordinate method and Lagrangian method, and the driving tbrce of PAM is determined. The experiment of body bending is conductcd, and the dynamic bending characteristic of bionic flexible body is evaluated. Experimental results show that the bending angle of the bionic flexible body can reach 18. An innovation body mechanism for quadruped robot is proposed, which has the characteristic of flexibility and achieve bending by changing gas pressure of PAMs. The coordinated movement of the body and legs can achieve spinning gait in order to improve the mobility of quadruped robot.
基金This work is financially supported by the National Natural Science Foundation of China （Grant No. 51075014）.
文摘A flexible-rigid hopping mechanism which is inspired by the locust jumping was proposed, and its kinematic characteris- tics were analyzed. A series of experiments were conducted to observe locust morphology and jumping process. According to classic mechanics, the jumping process analysis was conducted to build the relationship of the locust jumping parameters. The take-offphase was divided into four stages in detail. Based on the biological observation and kinematics analysis, a mechanical model was proposed to simulate locust jumping. The forces of the flexible-rigid hopping mechanism at each stage were ana- lyzed. The kinematic analysis using pseudo-rigid-body model was described by D-H method. It is confirmed that the proposed bionic mechanism has the similar performance as the locust hind leg in hopping. Moreover, the jumping angle which decides the jumping process was discussed, and its relation with other parameters was established. A calculation case analysis corroborated the method. The results of this paper show that the proposed bionic mechanism which is inspired by the locust hind limb has an excellent kinematics performance, which can provide a foundation for design and motion planning of the hopping robot.
基金the National Natural Science Foundation of China(60175029).
文摘The paper presents the design of walking leg for bionics crab-like robot, which is driven with micro servo motor. The kinematic characteristics of the bionics machine are analysed for optimized structure parameters, which has been used in the robot design. A three closed loop motor control system structure for joint driver is also given, as well as the multi-joint driving system for walking robot leg.
基金supported by the National High Technology Research and Development Program of China (863Program) under Grant No.2011AA041001
文摘A quadruped robot is more adjustable to a complex terrain than a wheeled or caterpillar robot to realize the continuous adjustable motions characterized by submissiveness and low energy consumption in basic control of the quadruped robot over rough terrain. This paper presents a static walking mode of ＂altitude hold＂, which means to keep absolute altitude by controlling limbs adjustably on the basis of which biokinetics studies have shown that quadrupeds can move with almost the same body altitude over rough terrains characterized by a nearly horizontal relief. The gait design specifies several characteristic states of stance phase and swing phase for a quadruped robot and controls the phase sequence and phase of four legs through change of characteristic states. Furthermore, we design a robot control system to generate adjustable gaits and control the coordinative movement of robot joints. This planning method is tested through ADAMS and MATLAB interactive co-simulation; the quadruped robot which has 8 degrees of freedom （8-DOF） is used to simulate the motion over a terrain character- ized by randomly arranged humps. The results show that this method can make the quadruped robot capable to walk over certain rough terrain.
文摘为满足仿生机器鱼目标检测的需要,在YOLOv5基础上提出了一种轻量级检测算法,降低算法复杂度并提高精度。首先对YOLOv5s模型进行改进,通过GhostConv和C3Ghost模块降低参数量和计算量。其次,引入CA和CoordConv模块增强特征提取和目标位置感知能力,采用soft NMS减少使用传统非极大抑制(Non maximum suppression,NMS)带来的漏检、误检,同时使用MPDIoU简化相似性比较,提升检测精度和召回率。最后,所提出方法在目标检测数据集上的试验结果表明,改进的YOLOv5网络体积更小、精度更高,证明了该算法的有效性和优越性。
