The Optimum Design And Dynamics Of A Kind Of Planar Robots With Actuation Redundancy

Parallel robots with actuation redundancy attract more and more attentionof researchers these years, because they can improve performance of parallelrobots. But their structure and actuated way are very complicated, so the studyof the mechanism design and analysis are also complicated, and there is littleachievement in this field on the world, therefore, there is very significantmeaning in theory and practice to studying them.The subject of this thesis is planar 2-DOF parallel robot with actuationredundancy, optimum designing the mechanism, analyzing its dynamics andstudying its control method. It can offer scientific gist in theory for the designand control study of this type of parallel robot.This paper study the relationship between the link lengths and theperformance of the planar 2-DOF parallel robot with actuation redundancy bymaking use of the physical model of the solution space, and plot the atlases ofthe workspace,dexterity,payload,velocity and stiffness global indices for therobot in the physical model of the solution space, and analyze the distributionlaw of the indices in the physical model of the solution space in detail.According to the workspace and these performance atlases, the basic designprinciples for the parallel robotic mechanisms are presented, the parameters areoptimized and a design example is given. On the basis of it, assembly structureof the manipulator is optimized. It is the reference for designers to designrobotic mechanisms by making use of kinematics performance.The mathematic model of dynamics for the planar 2-DOF parallel robotwith actuation redundancy is set up by Lagrange equation andLagrange-D'Alembert's equation in this thesis, and the dynamics of the robot isanalyzed.Based on the Simulink module of MATLAB, this thesis establish themodel of the planar 2-DOF parallel robot with actuation redundancy, and thesimulation for a typical motion is carried out and the kinematics state of theactuated joints are presented. According to the mathematic model of dynamicsof the parallel robot, through the program operation, the curves of the actuatedjoint torques are obtained.Two typical kinds of control methods_ PD control and computed torquecontrol are discussed and applied to the planar 2-DOF parallel robot withactuation redundancy, then the control block diagram of these two algorithmsare plotted.