Research On Design And Application Of Tne Soft Actuator For Frog-inspired Swimming Robot

With the development of society and the advancement of science and technology,human beings have continued to deepen the study of nature's biology,and bionic robots developed based on biological body structure and motion characteristics have been used in various fields.Bionic soft robots contribute to realize the miniaturization of bionic robots and improve the environmental adaptability of bionic robots.The fusion application of rigid and soft material characteristics can make bionic robots have a broader application prospect.This article took frogs as the research object and developed a frog-inspired swimming robot.Firstly,the frog's biological structure and the characteristics of the limb movement during the swimming process were studied and analyzed.The structural model of the joint-like pneumatic soft actuator was designed.The theoretical deformation analysis model of the actuator was established by using the Yeoh constitutive model and the virtual work principle combined with the geometric parameters of the actuator.When the overall size was constrained,the maximum output recovery torque at the end of the actuator at a certain bending angle was the target,and the structural parameters of the joint-like pneumatic soft actuator were determined.Then,3D printing,molding and other processing methods were combined to fabricate joint-like pneumatic soft actuators,and the form of the winding and the density of the winding,which were determined by the effect of the radial projection of the fiber line limiting actuator,were determined.The feasibility of the joint-like pneumatic soft actuator designed for frog-inspired swimming robots was verified by preliminary installation experiments.After experimental testing and analysis of the actual motion characteristics and the output torque characteristics of the joint-like pneumatic soft actuator at a fixed bending angle,the kinematics model and mechanics model were built to facilitate the subsequent regulation of joint-like pneumatic soft actuators to lay the foundation for the development of frog-inspired swimming robots.Second,the frog musculoskeletal system,the swimming mechanism and the mechanism and performance characteristics of the traditional rigid frog-inspired swimming robot were analyzed.Combined with the structural characteristics of the joint-like pneumatic soft actuator,the overall design scheme of the frog-inspired swimming robot was determined.The frog-like thigh and calf structure with rigid and soft features,the flipper structure with one-way stroke characteristics,the main trunk structure that met the robot's waterproof performance and exhaust performance,and the connecting structure of the adduction joints of the fore and hind limbs was designed.By analyzing the position and posture of the fore and hind limbs of the robot,the kinematics of the robot was simulated and the motion space of the frog-inspired limbswas drawn.The rationality of the mechanism design of the limb structure of the frog-like swimming soft robot was initially verified.Then,based on the analysis of the movement posture and intensity of the frog during the swimming process,combined with the kinematics and mechanical characteristics of the joint-like pneumatic soft actuator,the movement trajectories of the fore and behind limbs of the frog-inspired swimming robot were planned.Combined with the fitting movement model of the joint-inspired pneumatic soft actuator,the air pressure change curve of the actuator chamber during the movement of the frog limb was obtained.The control strategy of the joint-inspired pneumatic soft actuator was determined,and the effectiveness of the trajectory planning and control method was verified through experimental tests.Finally,the electrical system and the pneumatic system of the frog-inspired swimming robot were designed.The interaction relationship between the upper and the lower computer was determined and the software program was written.The overall design of the control system was completed and the uncontrolled movement of the robot was realized.The prototype of the frog-inspired swimming robot was built,and the robot's performance was tested through the prototype experiment,and the rationality of the structural design of the frog-inspired swimming soft robot driven by the joint-like pneumatic soft actuator was tested,and the reliability and correctness of its control system software and hardware were verified.