An XYZ Parallel Kinematic Flexure Mechanism With Geometrically Decoupled Degrees of Freedom

Abstract

A novel parallelkinematic flexure mechanism that provides highly decoupled motions along the three translational directions (X, Y, and Z) and high stiffness along the three rotational directions (خ¸x, خ¸y, and خ¸z) is presented. Geometric decoupling ensures large motion range along each translational direction and enables integration with largestroke groundmounted linear actuators or generators, depending on the application. The proposed design, which is based on a systematic arrangement of multiple rigid stages and parallelogram flexure modules, is analyzed via nonlinear finite elements analysis (FEA). A proofofconcept prototype is fabricated to validate the predicted large range and decoupled motion capabilities. The analysis and the hardware prototype demonstrate an XYZ motion range of 10 mm أ— 10 mm أ— 10 mm. Over this motion range, the nonlinear FEA predicts crossaxis errors of less than 7.8%, parasitic rotations less than 10.8 mrad, less than 14.4% lost motion, actuator isolation better than 1.5%, and no perceptible motion direction stiffness variation.