In this article,we study the trajectory planning and tracking control of a bionic underwater robot under multiple dynamic obstacles.We first introduce the design of the bionic leopard cabinet underwater robot develope...In this article,we study the trajectory planning and tracking control of a bionic underwater robot under multiple dynamic obstacles.We first introduce the design of the bionic leopard cabinet underwater robot developed in our lab.Then,we model the trajectory planning problem of the bionic underwater robot by combining its dynamics and physical constraints.Furthermore,we conduct global trajectory planning for bionic underwater robots based on the temporal-spatial Bezier curves.In addition,based on the improved proximal policy optimization,local dynamic obstacle avoidance trajectory replanning is carried out.In addition,we design the fuzzy proportional-integral-derivative controller for tracking control of the planned trajectory.Finally,the effectiveness of the real-time trajectory planning and tracking control method is verified by comparative simulation in dynamic environment and semiphysical simulation of UWSim.Among them,the real-time trajectory planning method has advantages in trajectory length,trajectory smoothness,and planning time.The error of trajectory tracking control method is controlled around 0.2 m.展开更多
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
Stingrays can undulate their wide pectoral fins to thrust themselves and swim freely underwater.Many researchers have used bionics to directly imitate their undulating mechanism and manufacture undulatory underwater r...Stingrays can undulate their wide pectoral fins to thrust themselves and swim freely underwater.Many researchers have used bionics to directly imitate their undulating mechanism and manufacture undulatory underwater robots.Based on the limitations of the existing undulatory underwater robots,this paper proposes a novel undulatory propulsion strategy,which aims to use the stingray undulating mechanism more thoroughly.First,the mathematical models of both traditional and novel structures are established to accurately describe their undulating mechanism.Then,based on the dynamic mesh technology,the flow field vortex structure they generated is analyzed through fluid-structure interaction simulation,and the thrust force and lateral force generated by them are calculated,which verified that this novel propulsion strategy is indeed more effective.Finally,a prototype robot based on the improved propulsion strategy is manufactured.Compared with the existing stingray robots,the prototype has obvious advantages,thus verifying the accuracy of the simulation results.展开更多
Bionic undulating fins, inspired by undulations of the median and/or paired fin (MPF) fish, have a bright prospective for un-derwater missions with higher maneuverability, lower noisy, and higher efficiency. In the pr...Bionic undulating fins, inspired by undulations of the median and/or paired fin (MPF) fish, have a bright prospective for un-derwater missions with higher maneuverability, lower noisy, and higher efficiency. In the present study, a coupled computa-tional fluid dynamics (CFD) model was proposed and implemented to facilitate numerical simulations on hydrodynamic ef-fects of the bionic undulating robots. Hydrodynamic behaviors of underwater robots propelled by two bionic undulating fins were computationally and experimentally studied within the three typical desired movement patterns, i.e., marching, yawing and yawing-while-marching. Moreover, several specific phenomena in the bionic undulation mode were unveiled and dis-cussed by comparison between the CFD and experimental results under the same kinematics parameter sets. The contributed work on the dynamic behavior of the undulating robots is of importance for study on the propulsion mechanism and control algorithms.展开更多
基金supported in part by the STI 2030-Major Projects under Grant 2021ZD0114504in part by the National Natural Science Foundation of China under Grants 62276253 and 62203435in part by the Beijing Nova Program under Grants Z211100002121152 and 20230484457.
文摘In this article,we study the trajectory planning and tracking control of a bionic underwater robot under multiple dynamic obstacles.We first introduce the design of the bionic leopard cabinet underwater robot developed in our lab.Then,we model the trajectory planning problem of the bionic underwater robot by combining its dynamics and physical constraints.Furthermore,we conduct global trajectory planning for bionic underwater robots based on the temporal-spatial Bezier curves.In addition,based on the improved proximal policy optimization,local dynamic obstacle avoidance trajectory replanning is carried out.In addition,we design the fuzzy proportional-integral-derivative controller for tracking control of the planned trajectory.Finally,the effectiveness of the real-time trajectory planning and tracking control method is verified by comparative simulation in dynamic environment and semiphysical simulation of UWSim.Among them,the real-time trajectory planning method has advantages in trajectory length,trajectory smoothness,and planning time.The error of trajectory tracking control method is controlled around 0.2 m.
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This work is supported by the National Science Foundation of China(No.91748123)the Natural Science Foundation of Shaanxi Province(Grant No.2019JM-145).
文摘Stingrays can undulate their wide pectoral fins to thrust themselves and swim freely underwater.Many researchers have used bionics to directly imitate their undulating mechanism and manufacture undulatory underwater robots.Based on the limitations of the existing undulatory underwater robots,this paper proposes a novel undulatory propulsion strategy,which aims to use the stingray undulating mechanism more thoroughly.First,the mathematical models of both traditional and novel structures are established to accurately describe their undulating mechanism.Then,based on the dynamic mesh technology,the flow field vortex structure they generated is analyzed through fluid-structure interaction simulation,and the thrust force and lateral force generated by them are calculated,which verified that this novel propulsion strategy is indeed more effective.Finally,a prototype robot based on the improved propulsion strategy is manufactured.Compared with the existing stingray robots,the prototype has obvious advantages,thus verifying the accuracy of the simulation results.
基金supported by the National Natural Science Foundation of China (Grant No 60805037)
文摘Bionic undulating fins, inspired by undulations of the median and/or paired fin (MPF) fish, have a bright prospective for un-derwater missions with higher maneuverability, lower noisy, and higher efficiency. In the present study, a coupled computa-tional fluid dynamics (CFD) model was proposed and implemented to facilitate numerical simulations on hydrodynamic ef-fects of the bionic undulating robots. Hydrodynamic behaviors of underwater robots propelled by two bionic undulating fins were computationally and experimentally studied within the three typical desired movement patterns, i.e., marching, yawing and yawing-while-marching. Moreover, several specific phenomena in the bionic undulation mode were unveiled and dis-cussed by comparison between the CFD and experimental results under the same kinematics parameter sets. The contributed work on the dynamic behavior of the undulating robots is of importance for study on the propulsion mechanism and control algorithms.
