In this paper, a dynamic model for an underwater snake-like robot is developed based on Kane's dynamic equations. This methodology allows construction of the dynamic model simply and incrementally. The partial vel...In this paper, a dynamic model for an underwater snake-like robot is developed based on Kane's dynamic equations. This methodology allows construction of the dynamic model simply and incrementally. The partial velocity is deduced. The forces which contribute to dynamics are determined by Kane's approach. The generalized active forces and the generalized inertia forces are deduced. The model developed in this paper includes inertia force, inertia moment, gravity, control torques, and three major hydrodynamic forces: added mass, profile drag and buoyancy. The equations of hydrodynamic forces are deduced. Kane's method provides a direct approach for incorporating external environmental forces into the model. The dynamic model developed in this paper is obtained in a closed form which is well suited for control purposes. It is also computationally efficient and has physical insight into what forces really influence the system dynamics. The simulation result shows that the proposed method is feasible.展开更多
In this paper, the kinematics and dynamics of an underwater quadruped walking robot were derived based on Kane dynamic equations. This methodology allows construction of the dynamic model simply and incrementally. The...In this paper, the kinematics and dynamics of an underwater quadruped walking robot were derived based on Kane dynamic equations. This methodology allows construction of the dynamic model simply and incrementally. The velocity and angular velocity components of an underwater quadruped walking robot were served as the generalized velocities. The forces which contribute to dynamics of an underwater quadruped walking robot were determined by Kane's approach. The equations of hydrodynamic forces of an underwater quadruped walking robot were deduced. Hydrodynamic coefficients were determined by experiments. The dynamic model was established by obtaining the generalized active forces and the generalized inertia forces. Numerical simulations of the walking behavior on underwater flat ground were implemented to verify the dynamic model of an underwater quadruped walking robot. Simulation results show that the dynamic model is correct.展开更多
A recently developed procedure to capture the dynamic stiffening of an arbitrary flexiblemember in large overall motion accompanied by small elastic vibrations is presented. A mechanicalsystem that consists of one or ...A recently developed procedure to capture the dynamic stiffening of an arbitrary flexiblemember in large overall motion accompanied by small elastic vibrations is presented. A mechanicalsystem that consists of one or more flexible members is called a flexible mechanical system. If thesystem is considered as a multibody system, the flexiblemember can be considered as a flexible bodyin a flexible multibody system. Having retained the nonlinearitites up to an appropriate point in theanalysis, the linearization is then performed properiy so that the dynamic stiffening terms can befound naturally, while the explicit formulation of the governing equations for the deformation mo-tion is ultimately linear. Based on the procedure, the effects of dynamic stiffening are investigatedqualitatively and quantitatively with analytical and numerical examples. The results are useful incomputer aid analysis of the dynamic behavior of flexible mechanical systems.展开更多
基金the National Natural Science Foundation of China(No.51009091)the Special ResearchFund for the Doctoral Program of Higher Education ofChina(No.20100073120016)
文摘In this paper, a dynamic model for an underwater snake-like robot is developed based on Kane's dynamic equations. This methodology allows construction of the dynamic model simply and incrementally. The partial velocity is deduced. The forces which contribute to dynamics are determined by Kane's approach. The generalized active forces and the generalized inertia forces are deduced. The model developed in this paper includes inertia force, inertia moment, gravity, control torques, and three major hydrodynamic forces: added mass, profile drag and buoyancy. The equations of hydrodynamic forces are deduced. Kane's method provides a direct approach for incorporating external environmental forces into the model. The dynamic model developed in this paper is obtained in a closed form which is well suited for control purposes. It is also computationally efficient and has physical insight into what forces really influence the system dynamics. The simulation result shows that the proposed method is feasible.
基金the National Nature Science Foundation of China(No.51009091)the Special ResearchFund for the Doctoral Program of Higher Education(No.20100073120016)
文摘In this paper, the kinematics and dynamics of an underwater quadruped walking robot were derived based on Kane dynamic equations. This methodology allows construction of the dynamic model simply and incrementally. The velocity and angular velocity components of an underwater quadruped walking robot were served as the generalized velocities. The forces which contribute to dynamics of an underwater quadruped walking robot were determined by Kane's approach. The equations of hydrodynamic forces of an underwater quadruped walking robot were deduced. Hydrodynamic coefficients were determined by experiments. The dynamic model was established by obtaining the generalized active forces and the generalized inertia forces. Numerical simulations of the walking behavior on underwater flat ground were implemented to verify the dynamic model of an underwater quadruped walking robot. Simulation results show that the dynamic model is correct.
文摘A recently developed procedure to capture the dynamic stiffening of an arbitrary flexiblemember in large overall motion accompanied by small elastic vibrations is presented. A mechanicalsystem that consists of one or more flexible members is called a flexible mechanical system. If thesystem is considered as a multibody system, the flexiblemember can be considered as a flexible bodyin a flexible multibody system. Having retained the nonlinearitites up to an appropriate point in theanalysis, the linearization is then performed properiy so that the dynamic stiffening terms can befound naturally, while the explicit formulation of the governing equations for the deformation mo-tion is ultimately linear. Based on the procedure, the effects of dynamic stiffening are investigatedqualitatively and quantitatively with analytical and numerical examples. The results are useful incomputer aid analysis of the dynamic behavior of flexible mechanical systems.
