Flexible Robotic Analysis

In this paper a survey of the literature dealing with dynamic analyses of flexible robotic manipulators has been done. Efforts has been made to critically examine the methods used in these analyses, their advantages and shortcomings and possible extension of these methods to be applied to a general class of problems. Modelings are subdivided according to the method of analysis and number of links involved in the analysis. Efforts have been made to include the works of a huge variety of researchers working in this field. There is a total of 433 papers created in the years 1974–2005 reviewed in this work.Robotic manipulators are widely employed to help in dangerous, monotonous, and tedious jobs. Most of the existing robotic manipulators are

The nozzle dam positioning task for maintenance of a nuclear power plant steam generator is an example of a task that requires a strong manipulator with very fine absolute positioning accuracy As pointed out before, flexible manipulators can find many applications but since the main problem is to control their vibrations, many researchers have tried to solve this problem by improving the dynamic models and incorporating different control strategies. In the following sections a review of the literature on modeling and control of the flexible links and joints is carried out. Though one may find even more references available in this field, here a total of 433 publications have been reviewed. It may be noted that a previous review in this work was carried out by many researchers.Developement of an enhanced equivalent rigid link system (ERLS) model using natural-mode shape functions for flexible manipulators and an experimental validation of the model was performed for a single-link manipulator. The Lagrangian dynamics and the finite element methods are used to derive the equation of motion. They have shown very low frequency modes due to joint flexibility and high frequency modes due to bending in the booms which results in significant end-point motion. Derivations of the dynamic model of a single-link flexible manipulator using FEM and then studied the

The review of the recent literature shows that limited research has been carried out for the design of a flexible manipulator with both joint and link flexibility. Also in almost all cases, linearized models of the link flexibility are considered which reduced the complexity of the model based controller. These models can not take care of even moderately large elastic deflections of the manipulator. Also, in most cases modal interactions which will lead to internal resonances are not considered and in the considered cases the study is limited to single-link only. In most analyses of multi-link manipulators only linearized models are considered. Hence there is a need to re-investigate the modeling strategy to incorporate large deformation, modal interaction, coupling of bending-bending, bending-torsion modes in the links. Very few researchers considered the possibility of modeling manipulators with composite materials. This will be an emerging research area where lot of work is required to control the flexibility effect. More analysis is required considering joint flexibility incorporating friction, clearances, etc. Also more experimental investigations are