.6-dof Parallel Robot Dynamics Modeling, Nonlinear Variable Structure Control

AbstractThis paper researches the 6-OF hydraulic-actuated parallel robot of large-scale lab model of Yanshan University. Firstly, the structure, development survey, and application prospect of 6-OF parallel robot are introduced. Secondly, some usual basic terms and concepts on robot science are given, one the base of which Lagrange dynamics model is set up and transferred into state-space one. And then the variable-structure system theory is described, including its research history and developing trend, sliding mode and its mathematical description and existence, quality of control system, control mode and reaching law. With the approaches in the paper, transformation of input-output is introduced , through which system becomes controllable regularity form. In addition, decentralized sliding-mode control, reason causing chattering and alleviation methods is also introduced. Finally, as to the state-space model of 6-OF parallel robot, the nonlinear variable-structure control methods are applied to the parallel robot dynamics control against the state-space model. The first step is transferring state model into controllable regularity form with transformation of input-output , the second one, using decentralized sliding-mode control theory to design decentralized variable-structure controller and the last step, summing up variable-structure controller of the whole system. In order to exam the correctness of theory, as in chapter 5, a great deal of simulation is done through the way of programming with respect to the 6-OF parallel robot nonlinear variable-structure control system derived. The result approves the rationality of design in the dissertation. And theoretically, the kind of design against the 6-OF parallel robot, high decoupled and nonlinear system, has attained the aims of.stability and stable decouple.