Research On Motion Control Of Autonomous Robotic Fish Based On CPG Method

With the development of science and technology,based on the development and utilization of land resources,people are focusing on the ocean,which accounts for 71% of the earth's area.As an important tool to explore the ocean,underwater biomimetic robot fish has become one of the hot spots of research.Researchers have done a lot of work in the design of biomimetic propulsion mechanisms,motion control,hydrodynamic analysis,etc.According to different propulsion modes,robot fish can be divided into body and / or caudal fin propulsion mode(BCF)and media and / or paired fin propulsion mode(MPF).Among them,in accordance with the basic swimming behavior control of robotic fish,more results have been achieved.In this paper,the motion control of autonomous robotic fish in a dynamic water environment is studied to improve its ability to complete tasks in a complex water environment.The main works are as follows:1.The research progress of bionic robot fish is summarized systematically.In view of fish swimming mechanism,bionic propulsion mechanism design,motion control technology,energy supply,and underwater communication technology,the research progress and main problems in the field of robotic fish are systematically analyzed.On this basis,the future research direction and development trend in the field of robotic fish are discussed from two aspects of engineering application and performance improvement.2.Based on the central pattern generator(CPG)model,a bionic robot fish motion controller is designed.Each degree of freedom of the pectoral fin of robotic fish is controlled by a CPG.On the premise of determining the phase relationship between the swing amplitude and the CPG,the swimming speed of robotic fish is controlled by changing the flapping frequency of the CPG unit.3.The dynamic model of robotic fish is given and its hydrodynamic characteristics are analyzed.On this basis,a closed-loop control scheme based on speed feedback is designed to adjust the frequency of each CPG unit and realize the tracking of the desired speed.The simulation results indicate the effectiveness of the algorithm.In addition,the research results show that the improvement of the swimming performance of the robot fish depends on the design of the propulsion mechanism which is closer to the fish in terms of flexibility or variable impedance,on the other hand,on the further understanding of the fish swimming mechanism and the improvement of the motion control method.The progress in these fields will provide important support for the engineering application of robotic fish.