Conceptual design, performance evaluation and dimensional optimization of a compact acceleration sensor based on flexure parallel mechanisms

In this paper, a tridimensional acceleration sensor based on flexure parallel mechanism (FPM) is presented. Three perpendicular compliant legs with compact monolithic structure are served as the elastic body for sensing the inertial signals in each direction. With integrated flexure hinges, each chain containing multiple revolute joints and cantilever beams are designed to carry compressive and tensile loads. Firstly, the structure evolution and kinematics modeling are introduced, followed by the multi-spring modeling of the directional compliance for the flexure leg. Then, the comprehensive finite-element analysis (FEA) including the strain of the sensitive legs, modal analysis for total deformation under different frequency is conducted. The compliances calculated by FEA and multi-spring model are compared. Finally, the dimensional optimization is implemented based on multi-population genetic algorithm to obtain the optimal flexure parameters. The proposed methods and algorithms are also useful for the analysis and development of other flexure parallel mechanisms.