Analysis And Calibration Of A 3-PRR Micro-motion Manipulator

As science & technology developments have led to requirements for high accurate manipulation, micro-motion technologies have become more necessary. They are playing important roles in accuracy manufacturing, semiconductor processes, biotechnology, micro surgery and other areas. Micro-motion manipulator is one important way to achieve micro-positioning.In this thesis a 3-PRR micro-motion manipulator is studied. The manipulator is a parallel robot with monolith structure, using piezoelectric actuators as its driving devices and flexure hinges as its kinematic joints. The micro-motion manipulator has a number of advantages, such as compact structure, small volume, high accuracy, high stiffness and strong anti-interference ability. The main research work of the thesis is listed as following:1. Kinematics and decoupling analysis of the 3-PRR micro-motion manipulator.The manipulator is a planar structure with 2 translational degrees of freedom and 1 rotational DOF. The inverse and forward kinematics of the 3-PRR mechanism is given. A simplification is made in the condition of micro-motion. Then based on the kinematics, the decoupling character is analyzed. 2. Stiffness analysis of the micro-motion manipulator.In the manipulator, flexure hinges are used to replace the traditional kinematic joints. First the flexibility on every direction of the flexure hinge is studied. A new kinematic model of the manipulator is built. Then based on the new model, the relationship between input forces and the output displacement is derived.3. Calibration of the micro-motion manipulatorIn this thesis, two calibration models are built based on kinematic model and stiffness model, respectively.The research work in this thesis is helpful to raise the accuracy of the micro-motion manipulator.