Research On Dynamics Modeling And Simulation Of The Space Flexible Manipulator With Uncertainty

The traditional dynamic model of the flexible manipulator is based on the certainty. The parameters of the model are considered as certain physical quantities, and they are accurate or can be accurately measured. But the dynamic model based on the accurate assumption cannot effectively describe the practical engineering problems, and may even lead to contradictory results. Because uncertainty is objective and inevitable. Based on Lagrange method, and concentrated on the uncertain phenomenon existing in engineering problems, the concept of Uncertain Dynamic Model of the Space Flexible Manipulator and its solution are proposed, and furthermore the Function Reliability of the flexible manipulator is studied.Firstly, based on Lagrange method, in use of the method of geometrical deformation constraint, together with the assumption of small deformation, the modeling method of flexible manipulator dynamics in consideration of rigid-flexible coupling are presented. The dynamic equations of flexible manipulator including the dynamic stiffening terms are established. And the dynamical equation is proved correct through the simulation.Secondly, uncertain characteristics are considered in the certain dynamic modeling of the flexible manipulator. Uncertain parameters were classified into three sorts as probabilistic parameters, fuzzy parameters and unascertained parameters. The form of existence and processing methods on the probabilistic parameters of the flexible manipulator are discussed. Base on above mention, the uncertain dynamic equation of the space flexible manipulator and its solution which is based on Monte Carlo method are proposed. By solving the uncertain dynamic equation, the mean and variance of dynamical response are obtained.Finally, the concept of Function Reliability is introduced based on multi-body systems dynamics considering probabilistic parameters. Systems not only realize specified motions but also the kinematic parameters of the systems remain within the specified range, which is the definition of function reliability. The performance function of the flexible manipulator is implicit, and aimed at this situation, the result of the function reliability of the flexible manipulator is calculated through Response Surface Method and Most Probable Point Method based on BP Neural Network respectively in the dissertation. The superiority and inferior positions of the two methods are also compared to ascertain their application areas.