Design of a Double Triangular Parallel Mechanism for Precision Positioning and Large Force Generation

This paper presents the design of a double triangular parallel mechanism for precision positioning and large force generation. In recent years, with the acceleration of miniaturization in mobile appliances, the demand for precision aligning and bonding has been increasing.Such processes require both high precision and large force generation, which are difficult to obtain simultaneously. This study aimed at constructing a precision stage that can perform submicrometer resolution alignment, several-hundred micrometer stroke, and several-hundred Newton force generation.Piezoelectric actuators were tactically placed to constitute a parallel mechanism with a double triangular configuration. In addition, flexure hinges were carefully designed and optimized. The three actuators in the inner triangle function as an in-plane positioner, whereas the three actuators in the outer triangle as an out-of-plane positioner. To facilitate rapid control of the developed stage, two mapping matrices were derived from the inverse and forward kinematics and the corresponding iterative numerical calculations. Finite-element analyses and experimental results proved that the developed stage with the double triangular configuration sufficiently met the requirements of precision positioning and large force generation.