Research On The Dynamics And Control For 3-RRRT Parallel Manipulator

This paper researched the 3-RRRT parallel manipulator which have been designed by TianJin University of Technology. We formulated the kinematics of the manipulator according to analysis of the position and posture.On this base, the dynamics model of 3-RRRT parallel manipulator was developed and transfered into state-space model. And then we researched the state-space model through applying the nonlinear state-feedback decoupling approach to the dynamic control of 3-RRRT parallel manipulator system, got the nonlinear state-feedback decoupling control law according to differrential geometry control theory. In order to stabilize the nonlinear decoupling control system of the parallel robot, an assuaging control law is developed further, so that 3-RRRT parallel manipulator close-loop system was not only decoupled but also stably decoupled. We also used the variable-structure system theory in this parallel manipulator system.The nonlinear variable-structure control methods were applied to the parallel manipulator dynamics control against the state-space model. The first step was transferring state model into controllable regularity form with transformation of input-output, the second, using decentralized sliding-mode control theory to design decentralized variable-structure controller,the last, summing up variable-structure controller of the whole system. In order to exam the correctness of theory, in the last part of every chapter, we used the simulating software MATLAB, the correctness of theory was done through the way of programming .The result approved the rationality of design in the dissertation. And theoretically, the kind of design against the 3-RRRT parallel manipulator, high decoupled and nonlinear system, had attained the aims of stability and decouple.