Design And Synthesis Of Flexure Hinges And 3-DOF Micro-motion Planar Parallel Manipulators

Flexure hinges and parallel manipulators have widely been used in the area of micro operation because of their outstanding advantages. 3-DOF planar parallel manipulator (PPM) belongs to a very important member in parallel manipulator's family and there is wide application foreground as well as developing value in the area of micro-operation due to its simpleness in structure , feasibility in control and cheap development cost, as well. In this paper, the design and synthesis of flexure hinges and micro-motion manipulators in the field of micro manipulation are studied, so it will help to develop novel micro manipulation parallel robot systems. The following is research we carried out.First, the classification of 3-DOF planar parallel manipulators is introduced, then, a new classification about them is built based on their forward kinematics, which is characterized with simple and practical properties with comparison to the conventional Merlet method. Following is the forward and inverse kinematic modeling derived as well as solutions.Then, to one of the key techniques of micro operation manipulator-the problem of design of compliant joints, two novel joints are developed with cosine profile and hyper cosine profile. Their compliant coefficient expressions in the compliance matrix are derived by use of Castigliano's Displacement Theorem, or strain energy theory. Furthermore, the changes of stress and deformation under various loads are studied with finite element approach, and their features have been obtained in comparison with those of the general applied semi-circular profile's flexure hinges. After this work, the Added-Deformation Method is introduced by consideration of the effect of non-functional deformation under load, and the coordinate transformation of flexure hinge is also offered.Meanwhile, as a case study of 3-DOF planar parallel micro operation manipulator, the modeling and solution to kinematics and dynamics of a RRR micro-motion manipulator are presented. By use of Differential Motion Method, Loop Moving Chain Vector Equation, simplified and linear kinematic models and dynamic models are obtained; the Kino-static model is also gained by a combination of kinematic equations and static balance equations with Pesuo-Rigid-Body Model and Added Deformation Method, respectively. Solving process and the differences in motion precision are demonstrated also.Finally, to the prototype of 3-DOF micro-motion manipulator, the three constant Jacobian matrices have been obtained with linearly simplified modeling approach, finite element approach, and experiment, respectively. Their corresponding workspaces of the stage are obtained and the validity of this study is verified through synthesis and comparison among them.