| With the development of bionics,material science,automatic control theory disciplines,the idea of using the swimming propulsion mechanism of fish to realize the propulsion of underwater vehicles and underwater robots has gradually become a reality.In recent years,bionic underwater robot has become an important development direction in the field of underwater vehicles.For bionic underwater robot,the research of kinematics and dynamics is an important part.In this paper,the kinematics and dynamics of a small four joint bionic mechanical fish are analyzed and simulated.Firstly,this paper designs the mechanical structure of bionic mechanical fish according to the actual needs.Using the body wave envelope equation of mechanical fish and the motion control method of sinusoidal controller in the motion control method of bionic mechanical fish,the swing equation of each joint during horizontal swimming is solved.Combined with the hydrodynamic calculation results of four joint mechanical fish,the ADAMS simulation model of four joint mechanical fish is built.Using the built simulation model,the simulation analysis of the mechanical fish is carried out,including the correlation between the swimming speed of the mechanical fish and the maximum swing angle amplitude of the tail fin,the correlation between the swimming speed of the mechanical fish and the swing frequency,the sdruhar number of the mechanical fish and the turning performance of the mechanical fish.The correlation equation between the swimming speed of mechanical fish and the maximum swing angle amplitude and swing frequency of caudal fin and the optimal value range of the maximum swing angle amplitude of caudal fin are obtained.Secondly,the dynamic equation of four joint bionic mechanical fish is deduced by using Lagrange dynamic equation.The dynamic simulation of the mechanical fish without considering the diving motion is completed.The relationship between the joint torque and the swing frequency of the mechanical fish and the relationship between the joint torque and the swing angle amplitude of the mechanical fish tail fin are analyzed.Combined with the simulation results,the model of the joint driven steering gear is selected.Finally,combined with the actual needs,the method of changing the center of gravity position is selected to control the diving motion of the mechanical fish,the design of the diving control structure of the mechanical fish and the derivation of the pitching moment change equation are completed,the virtual prototype of the diving motion simulation of the mechanical fish is built and the simulation is completed,and finally the pitching angle change curve and angular velocity change curve of the mechanical fish are analyzed. |
