Rigid-Flexible Coupling Design Of Biomimetic Robotic Fish And Its Cruising Performance Optimization

Fish are able to maintain high cruising stability and propulsion efficiency in various states of motion due to their inherent ability to coordinate their multiple fins and adjust their body flexibility.However,even bio-inspired robotic fish incorporating various advanced technologies still fall far short of real fish in terms of performance.This academic paper discusses how fish use their multiple fins coordination and body stiffness adjustment mechanisms to achieve efficient and stable movement,and optimizes the swimming performance of robotic fish based on this bio-inspired approach.The main research contents of the paper are as follows:The structural design and mathematical modeling of a rigid-flexible coupling bio-inspired robotic fish.To simulate the swimming process of fish in water,this paper proposes a scheme for a rigid-flexible coupling bio-inspired robotic fish and analyzes it mathematically.The fish is equipped with a caudal fin,a tail fin,and two pectoral fins for multidimensional movement switching.The rigid-flexible coupling structure of the tail fin propeller enables controllable flexibility and stiffness of the body,achieving better propulsion efficiency and stability.Mathematical modeling is based on the theory of dynamics of rigid bodies and the Pseudo-Rigid-Body Model(PRBM),which verifies that the robotic fish has good motion performance.Multiple fin coordination control to improve the motion stability of bio-inspired robotic fish.This paper proposes a solution to the yaw problem of bio-inspired robotic fish: coordinated control between the tail fin and the caudal fin to improve motion stability.The scheme uses a rigid-flexible coupling bio-inspired robotic fish that can achieve three-dimensional multimodal movement as the experimental platform,and adopts a controller based on the Central Pattern Generator(CPG)to coordinate the motion of the caudal fin and the tail fin.The experiment uses online motion parameter adjustment to explore the comprehensive effects of different flapping frequencies,flapping amplitude,and phase difference between the caudal fin and the tail fin.The experimental results show that proper coordination control can improve the motion stability of the robotic fish and increase the stability by 65%.Optimization analysis of driving performance for a multi-proportion rigid-flexible coupling fish body.To further optimize the propulsion performance of bio-inspired robotic fish,this paper explores the multi-factor influences of coupling ratio,flexible body stiffness,flapping frequency,and flapping amplitude on swimming performance,and conducts a driving force optimization experiment.The data results show that to maximize the propulsion force of the robotic fish,it is necessary to lower the coupling ratio of the fish body to adapt to its low-frequency motion state,while it needs to increase the coupling ratio of the fish body when the robotic fish adjusts to high-frequency motion.The research results of this paper provide useful ideas and methods for the design and optimization of bio-inspired robotic fish.By analyzing the multiple fins coordination and body flexibility adjustment mechanisms of fish,and combining the structural design and mathematical modeling analysis of the rigid-flexible coupling bio-inspired robotic fish,this paper provides a practical solution to the problem of motion stability and propulsion efficiency of robotic fish.In addition,this paper also studies the importance and influence of multiple fin coordination control and multi-proportion rigid-flexible coupling fish body driving performance optimization to improve the swimming performance of robotic fish.By integrating these research contents,the results of this paper provide new ideas and directions for the design and promotion of future bio-inspired robotic fish,with certain application value and promotion significance.